how to be a manuever/attacker in the middle game?

Well, simply said.. Attacker doesn't mean u throw all your pieces to the opponent's king. maneuver ur pieces 1st to good squares. if u can't, then make one! making weak squares/pawns are also a part of attacking. Well, to be a good attacking player, u should watch other pros (masters) play! Chessmaster 10th edition is quite a nice programme if u ask me as the way it teaches and explains chess games is just like a good teacher talking to his disciples (actually it's from Josh Waitzkin and Larry Christiansen).