What color squares should pawns be on with one bishop left? This slightly confuses me.  If I have one bishop left - let's say it is the light-squared bishop - ss it better for my pawns to be on the light squares or dark squares?  Let's assume also that my opponent has a dark-squared bishop.  The way I look at it it is like this (which is probably wrong).  If my pawns are on the light squares, I can protect them with my bishop, but they block my bishop.  If my pawns are on the dark squares, they don't block my bishop, but I can't protect them.

Does it make a difference if the opponent has a bishop left that is the same color as yours, or has no bishop left?
The rule of thumb is that the stronger side (the side trying to win) should put the pawns on the opposite color of his or her bishop (so that they don't get in the way), and the weaker side should put pawns on the same color as their bishop in order to defend them an extra time (defended with the bishop and the king, the opponent can never win a pawn).

There are obviously exceptions to this, though.  Each position really has to be judged independently.  

One key idea, however, is that it is usually a good idea to block your opponent's pawns on the same color as the bishops (assuming that the two bishops are both light squared bishops or both dark squared bishops).  This gives you the chance to try and win the pawn later and it will restrict the movement of your opponent's bishop.  

If you have the only bishop on the board (your opponent has a knight, for example) it is almost always correct to put the pawns on the opposite colored squares of the bishop.  This is usually the only way to play for a win.  This touches on the good bishop/bad bishop question, but if your bishop is bad, then the knight will many times have the edge.  If your bishop is good, however, you can try to make use of the bishop's superior range.