Quote Originally Posted by Sir Pawnalot
Why is aggression good?

1. Bigger pots
2. Can win without showdown. (stealing equity)
3. Gain more information. Lose less with second best hand.

Aggression for the sake of aggression is no good. Understand the reasons behind your actions and chose your spots.
This is right on the mark. Always know the reason you are making a raise. And even more importantly, stick to those reasons. If you raise w/ bottom pair to see if you are ahead and get re-raised, you probably need to let it go unless you have an ironclad read on you opponent. On the other hand, if you have top 2 and value bet and get re-raised you should already know if you are going to call with intention of check raising the turn or re-raising the flop. Sure you won't always be making the right decision, but you will be starting to think about the whole hand and not just the flop