I'm an average player, I know most of the guidelines that one should consider in the game. But what gives me the most hard time is when my opponent starts pushing his/her pawns, and even when i try it myself, i can't hold a good formation, it gets destroyed easily. So any advice about how to defend against a pawns storm? Or how to maintain pawns formation?

Thanks,

ImadStein.

"The pawn is the soul of chess."- PHILADOR. 

Know the value of the pawn. You can refer some games played by GMs for knowing how they utilize pawns at the biginning ,middle game and end game.

For basics you can refer

http://en.wikipedia.org/wiki/Pawn_(chess)