Welcome to the chaos strategies page. I hope that these will help you win some games in the future.
Ill start with your chaos lord. Depending on what role he will fulfill equip him accordingly. If you want a close combat monster then use terminator armour with a lighntning claw and give him a displace field,combat drugs and a daemon weapon. Otherwise you should equip him as you see fit, but that is THE close combat fit. Next the icon bearer. One with a mark of slaanesh,chainsword and powerfist, carrying the flesh banner and allure of slaanesh will mince people in HTH. But if your purpose is to bolster Chaos marines already formidable LD then give them a banner of one of the chaos gods. Champions and aspiring champions should be outfitted according to their battlefield role.
Squads. The arguably best infiltrators in the game (besides lictors?) are chaos veterans. Assault weapons allow you to earn summoning points for Khorne on the first turn. While heavy weapons and hard cover will draw the heat from your other chaos squads allowing them to advance unscathed. Basic chaos space marine squads are the backbone of your army and should always be given a special weapon, but not necessarily a heavy weapon. Marked squads are the staple of your special troops. Khorne bezerkers are you best assault troops wth their frenzy and furious charge. They need assault weapons of course, preferably a chainsword. Plagurmarines are great at surviving basic weapons fire so you can use them more boldly than your basic chaos marines. Slaanesh noise marines are basically used to cut down multitudes of troops (imperial guard, orks) with their sonic blasters and doom sirens. finally thousand sons marines are the most likely to stand their ground till the bitter end as they don't take break tests. But beware that D6 will die if energy drain is played. Also beware of these specialist troops which cost more and die (in a few cases) just as easily.
Tactics. You can use basically any kind of tactics and win by a small margin but here are a few favourites. Use assault troops to take one flank (daemons come in here, more later) then assault the flanks of their main force. Your other troops advance with no harm to them (you will loose you assault troops) and you can exact a heavy toll on you enemy. The other thing you can do is play defensively. This is one of the easiest things to do (rapid fire you know) and will make it difficult for you opponent to harm you substantially.
Daemons. They are close combat monsters and are best used to support your assaults. Greater daemons are a mixed bag. Remember if you posses a champion behind their lines then you can be sure that that daemon will die because of the amount of heavy weapons brought to bear on it.
Anyway if these work, congrats, and if not, then try developing your own style. But always remember that these are not an end in their own, but are only a beginning. feel free to develop your own tactics (and if they work mail 'em to me and ill credit you with them when i put them up).
Enjoy. Thanks for sticking with me throught this.
Special thanks to Jay Lichtman for providing the background for this page. Thanks, Jay.