Check out the CC articles
. Great stuff there that can teach you both the basics and more advanced stuff.
Additionally i am using Harrington's M factor to help determine aggression level and style of play. The M gives you a good idea of your standing and expected lifetime in relation to your stack. The M is calculated:
M = Stack / BB + SB + Ante
A M above 10 is desired as it shows how many rounds your stack will survive on its own.
Example: You're in a stars mtt after the first break. Your stack is 2200, the blinds are 100 / 200 and the ante is 25. Your M is:
2200 / 100 + 200 + 25 = 6.8 M
So your life expextancy in the tournament are dwindling (down to 6,8 rounds at the current level). You need to start playing harder and stop peeping at flops with questionable hands. Either you hit a monster and get paid - or you pretend to hit a monster and scare the competition off - or more likely: You hit a semi good hand and have to play it like a monster either scaring everyone away or hope for luck on the board.
Using M in MTT's also requires you to consider rising blinds and antes. A reasonable M can quickly translate into a bad one, once the blinds and the antes go up. So keep an eye on the time left on each level.