SPACE MARINES: WARRIORS OF FAITH
Well here we go. What kind of player you are defines what kind of force you pick. If you are a very defensive player your force will consist primarily of tactical and devastator squads, with chaplains and standard bearers mixed in to ensure that morale doesn't fail. You know that these squads will be, by basic natutre hard to destroy, but wiht the addition of chaplains and standards they will be even harder to either break or defeat in HTH combat. The other bits you can use would be terminators to hold a defensive strongpoint, or to support your other squads.
The agressive player will use Lots of tactical and assault marines to hurry the battle onto your enemy. Your characters should equip for hand to hand combat and be equipped with jump packs to accompany your assault squads. The best characters to arm in thsi way are power armoured captains and high ranking chaplains and other suitably "hard" characters. Anything with high weapon skill and power armour are the best thing to put in assautl squads. Terminator are also marvelous at advancing through fire unscathed to deal death with their lightning claws and their thunder hammers.
The vehicles that the defensive players pick are hevaily laden predators armed with lots of lascannons. This is the mainstay of Space marine armies (often in place of the devastators). The other good piece of equipment is the rhino which can ferry your defending troops to where they need to go.
The land speeder and bike is the mainstay of the assaulting army. These are devastating when used to soften up the part of the line where your assault marines will atfack. Here is where scouts are pretty useful, and for the same reason. Shotguns can stop a charge in its tracks and needle rifles are great at gunning sown troops with impunity. The only problem with scouts is this: one squad rarely survives the battle, but two or more will be a royal pain in the ass for the entire battle. Librarians should also be chosen along the same linnes as the troops above and they are very much like a mobile weapons platform, but one which has the ability to maul many things in hand to hand combat.
Tactics? Well you should defend behind obstacles and rapid fire with the defensive army and the assault army should be always on the move, moving to hit a different part of their enemies force at every turn. The assault marines, scouts and land speeders and bikes should all attack one flank and then move from one flank up throughh the canter of the enemy to the other flank to destroy their enemies wholesale.
I hope you enjoyed these army list thought and strategies, and aloha.