I'll throw in my own two cents about playing heads up here.

1) Aggressiveness is KEY (as stated before by rippy) -- but it can also get you killed by a player who recognizes your strategy (therefore, try not to let your opponent see your cards often)

2) Pocket pairs go up in value tremendouwly -- taking what rippy said one step further. Going all in with ace junk can win a few hands against KQ, but pocket sixes have even greater potential.

3)I want to act last as often as possible whether it's to get a free card, or to make my opponent tell me something about his or her hand before I have to act. Information is rarer and thus, more important to get in heads up. Usually, if I'm going to fold, it's in the small blind. If I ever do play a hand out of the sb, I make sure to put in an imposing raise. Try not to ever simply call in the sb, unless you are sure you want to show weakness.

4) Post flop, be willing to go farther when you pair any card on board. Also, loosen up when you're holding overcards (not too much, obviously) because you may be able to bust a guy who paired 7s and doesn't believe that you paid to the river to pair your king.

That's it for now, maybe more later.