Ah the Space Marine tactical squad how we've come to love the all rounded good fellows. If your not sure with what to do with tactical marines then have a read of this quick tactica.
The generic Space Marine has some of the most balanced stats in the game along with a above average armour save. The Marine can shoot well hitting on 3's, hit well in combat, strike fairly quickly and has a leadership value of 9 with a sgt.
Wargear you get the trusty boltgun, rapid fire for two S4 AP5 shots or shoot once for a 24" range. T3 models will go down fairly easily. Throw in a bolt pistol incase you fancy shooting and charging and then frag grenades to make sure the Marines don't go last in assault if assaulting through cover and krak grenades if they run into pesky walkers or tanks.
To make these all rounders even better they have a few special rules, first is And They Shall Know no Fear, which basically means they pass tests to regroup (normal restrictions apply) and as a added bonus they cannot be destroyed via sweeping advance, ok this entails the no retreat! rule, but your precious Marines don't get wiped off the table, mix this in with the next rule, combat tactics and you have a winner. Ok no retreat! rule is a bit of a bummer, but its a mere price for not getting swept after loosing combat.
Combat tactics allow any none fearless Space Marine unit to automatically fail a morale test. So the next turn is yours, and you're currently locked in combat. If you lose combat, choose to fail the morale test and fall back, remember you cannot be destroyed by sweeping advance so you still have your squad, but no retreat! may claim one or two models. Next turn you can then rapid fire or use bolt pistols and charge back in. A simple but affective tactic which works well.
Combat squads allow Space Marine units of full strength (10 models) to be split into two units of 5. As tactical squads get a free special and heavy weapon this can be of use. Spilt your squad and have the heavy weapon and four other Marines camp it out, the special moves in. This way you don't need to worry about moving and shooting because of the heavy weapon and throw your sgt with the special and you can use the assault special weapon more effectively by using the sgt's extra attack and access to power weapons in close combat. Disadvantage to combat squads is kill points, each combat squad is worth a kill point, so your tactical squads become worth 2 kill points! Keep this in mind on kill point missions ;) . Now that is a downside, but plus side is 1/3 of the standard missions are objectives, so you take 3 tactical squads split them into combat squads and you now have 6 objective capturing units - nice! :D
The tactical squad has access to a fair amount of weaponary, though you do need a full unit to access this so your hands are tied by taking 10 models, but with combat squads who cares.
The squad has a choice of 3 special weapons, a flamer which is free, a meltagun for 5 points and a plasma gun for 10 points. Flamer is good for hordes, but is close range. Meltagun excellent for armour and a high chance of a kill. Plasma is for tough infantry.
The heavy weapon choices are all out there, 6 choices in total and 3 of them are free. Heavy bolter, multimelta and missile launcher are all free. H.B is for anti horde, multimelta vehicles and missile launcher is middle ground able to fire frag and krak missiles. A plasma cannon is only 5 points, a good buy and a lascannon is 10 points which isn't too bad.
The seregant has a massive range of wargear, combi weapons are good if you take a power fist or lightning claw as these do not get the bonus attack, but only if you have the points. I don't feel that a storm bolter is worth the upgrade really as the Marines if they move can fire twice 12", or once 24" if keep still - the storm bolter has the same firing range and always fire twice, just keep the bolter. A plasma pistol can come in useful, but I wouldn't add any other wargear onto the sgt because if the sgt rolls for gets hot! and fails the armour save bye bye sgt, bye bye 15 points plasma pistol and bye bye 25 point power fist - 40 points gone all because of your own dice rolling!
I like power weapons. Some people don't. Tactical squads aren't the surpreme assault unit, but they can hold their own. Once I had a unit of 10 Chaos Marines (have the same profile but 1 more attack) and I had no power weapon. I charged 5 Space Marines, the sgt had a power fist. I lost combat after several turns, if I would have taken a power weapon I would have killed them. Taking a power weapon can help you in combat and cut through numbers more. It can be worth it, especially if you kill 1 or 2 models a turn then the power weapon pays for itself. I also like power fists, ok they go last but S8 is more than enough in return. These can smack tough infantry and deal with walkers, I find these a lot better than melta bombs and it would pay to have at least one on a sgt - but best only add a power weapon or power fist on a sgt in a combat squad with the special weapon, you can then assault and use the power weapon. You don't want to drag all 10 Marines into the fight and keep that heavy weapon locked out of use.
Tacticals get access to 3 dedicated transport units, the reliable Rhino, Razorback and a Drop Pod.
Personaly, I like the Rhino the best, its more mobile, not open topped like the pod (so no +1 on the damage chart) and two Marines can shoot from the top hatch without taking any damage. Ok it has less armour, but you do have smoke launcher so you can get a cover save. The Rhino gets a few bits and pieces of wargear, nothing to write home about and really I'd only upgrade with these if you either play on a heavy terrain board (dozer blade) or have the points.
Best thing for a Rhino is to use the short ranged multimelta and either a flamer or meltagun from the top hatch. Move the Rhino forward, what you can do is do something called a "Rhino train" which Rhinos hide behind the first one in a train like fashion. Another trick I liked to do is stagger them, so the first one gives cover to the second. The one at the front pops smoke first turn, gives it a cover save, the one behind uses the first Rhino for cover. Next turn switch them around so the Rhino at the rear now goes at the front, pop smoke and both get another cover save again. Always use the Rhinos in pairs or more for this tactic, but pairs is always best for mutual support.
By turn 2 you should be in range with the multimelta. A flamer is useful as you need to get into range with the multimelta, so in case you get chargem, or enemy units come close by you can BBQ them. The meltagun is nice and doubles your melta efforts, but I think the multimelta does the job here. Problem with this tactic is you cannot use combat squads as these are split in deployment, but the multimelta should be in range by turn 2 with the above tactic keeping the Rhinos going and be in range of other targets. Also if your using combat squads with Rhinos you're passing half of the Rhinos transport capacity up, bit of a waste. Nothing beats a drive by shooting IMO! If you want to split into combat squads, then you'll like the next customer...
I use the Razorback in my Imperial Fists army is makes so much sense to use combat squads and throw the sgt and special weapon in a Razorback and use the heavy weapon combat squad in a static location. Now the Razorback doesn't have a hatch, so no shooting out of but it does have a twin linked heavy bolter as standard. The heavy bolter is great for providing covering fire at long range units, or supporting fire before going into a assault. It can also pop lightly armoured vehicles too. For a extra 5 points, and if your using combat squads and want a full mech list Razorback is the way forward.
The Razorback can upgrade its heavy bolter for four other twin linked weapons, a assault cannon, heavy flamer, lascannon and lascannon and twin linked plasma gun. Personaly I like to keep my transports cheap, Razorbacks aren't the most durable so you don't want to invest loads of points into a fire magnet which dishes out the pain. All the upgrades are expensive, I don't thinka heavy flamer is worth it as the hatches are at the side and rear to disembark and the turret at the rear. The template won't reach far and you will need to get in the face with your tank to do damage, do this and you might not be able to disembark your troops. Assault cannon is over costs, for a extra shot better ap, strength and rending its not worth 35 points. Lascannon I would only do if you lack anti tank. The lascannon and twin linked plasma gun is add combination, a strong anti tank weapon mixed with a heavy infantry light vehicle weapon, either would/could be wasted. I think this is a novelty as its something new so I wouldn't bother.
Also, like the Rhino they come with smoke launchers and the staggered tactic will work, but mental note you cannot fire smoke launchers and other weapons also ;) And remember, try and pop smoke on your first turn, providing your transport has no cover.
Last but not least is the Drop Pod, which now has a model too, finally. The pod basically deep strikes your Marines and gives a aggressive attack. But once your Marines are in they can only shoot, because they have entered via deep strike they cannot move and must disembark from the pod. So next turn your opponent is going to let you have it, big style.
As well as dropping your Marines in the thick of it and providing no cover the pod also brings a bit more negative to the table. Its armour 12, which is ok but its open topped which means +1 on the vehicle damage table, oh and its immobile. Score a immobilised result its weapon destroyed, if the weapon is destroyed already then that result is changed into wrecked. If your playing kill points I think a drop pod would be a easy target.
The pod does have a weapon upgrade, a deathwind launcher. Could be useful for wiping out units when you pod in, but becareful it doesn't scatter onto your own men.
With drop pods I'd rather let another unit have them. The Marines need to be mobile, after all they are called tactical for a reason! Once dropping in with that heavy weapon you cannot move and shoot, so one or the other. Ok with a Rhino you can get the same thing, but at least your models are protected and can be more mobile - ok cannot shoot the multimelta on the move, but can get to the target quicker. TBH I'd rather use the pod for say a Dreadnought which can hold its ground, and then its in assault range which it can excel at - depending on units its against.
At the end of the day I've fought and used a Drop Pod Marine army, I don't rate them. They start off aggressive and may do damage but after that it all comes back on them. Either they wipe out the target and now are foot slogging, bad choice. Or don't wipe out the target and get blasted the next turn. Kill points easily obtained by wiping out the squad in the pod, and then destroying the pod, remember its open topped and immobilised so easy damage.
Rhino is the old fashioned boy which is great for out the hatch up close and personal attacking. Works well with a multimelta and flamer combo, and for 35 points its cheap. You could probably use a plasma cannon in there as well.
Razorback is now in the spot light and as if combat squads were fashioned for it instead of being a combat squads chariot. Use it as a fire bunker if its immobilised, use it to provide covering and supporting fire for your squad once out in the open or use it to take out light armour. Forget its weapon upgrades, way too costly.
I'm probably biased here, but I would go with a Razorback as it goes hand in hand with combat tactics. Leave behind a missile launcher or lascannon. Rhino flanks in second followed by the Drop Pod.
Rhino setup would be a multimelta and flamer, if they bum their assault range you can BBQ them next turn. Throw a plasma gun in if you fancy doing more damage, but really a multimelta is all for vehicles.
Razorback is fine with the heavy bolters, use a meltagun with a sgt with a power fist to do the nasty on vehicles. If you fancy anti troop go with a plasma gun, maybe a flamer with a sgt with a power weapon.
Drop Pod a multimelta gets up close and personal, meltagun would be great as well. Same tactic as the Rhino as your tactical squad is a whole unit, but once you've dropped in thats it your on your feet now.