Originally posted by orion25
just make shure you don't leave your pieces hanging and the rest will take care of itself
I agree with orion25. I took a brief look at some of your games, and it seems that you're at the stage where you are giving away pieces. Everyone goes through this stage, but you don't want to get stuck there. I recommend practicing with a tactics server like http://chess.emrald.net/
to help you develop your tactical vision. Once you gain more confidence in this area, you can work on pawn structure.
As far as pawn structure goes, some things you want to keep in mind are doubled pawns, isolated pawns, passed pawns, pawn chains, pawn islands and moving the pawns in front of your castled king. In general, doubled pawns, isolated pawns and moving pawns in front of your castled king have negative positional consequences, but these negative consequences are sometimes more than outweighed by positive positional or dynamic advantages. For instance, doubled pawns are often more easily attacked and require piece-support for defense, but they can increase your influence over the centre, prevent penetration of opposing pieces into your camp or provide good outposts for your pieces. It's up to you to evaluate the possibilities and make a decision as to which aspect (positive or negative) is more important in a given situation.