One Tidbit: To be sitting decent for post 1 hour play, you will want to have about 10-12k by the first break. Average is ussually 5-7k, with some monster stacks at 35-40k. 10-12 seems to be the normal 'Goal' to attain during the first hour.

Edit: A few more things... The first responder was correct in saying "Don't be afraid to take chances."

There is a lot of all in action at most tables during the first hour (especially the first level or 2). When you are 60/40 or better you need to be ready to have your chips in the pot and hope for the best.

Also - if you are not prepared to rebuy do not play, though it is probably smart to give yourself a limit. I personally give myself the buyin +5. A lot of people suggest an immediate rebuy, I personally do not. Often times I can make it through with just my original buy-in (doubling in the first few hands) and then the hour add on. But if I rebuy, I double rebuy at that point. I allow myself 2 double rebuys (in addition to the add on and the buy in).