Chess books about Attacking Chess

Attacks against the castled king are usually justified by some imbalance: you have more firepower on the king's side than your opponent, or the opponent weakened his king's position by moving one of the pawns in front of the king.
Many mating attacks are introduced by sacrifices: if mate is the goal, material doesn't matter anymore. The queen is almost always the most important piece in a mating attack, since she has various ways of mating a king. The most common is a direct 'contact check' while being protected by one of her own pieces. For instance, white knight g5, black king on g8 and the queen mates at h7, or black bishop at f6 or h6 and the white queen on g7 mates the black king on g8.
Don't assume that every move in a mating attack has to be a check. Often, a check just drives the king to a better position, or weakens your own setup. Try to find 'quiet' moves which seal the deal.