Don't Fall in Love with Your Queen
Time and time again, I keep hearing a common theme from beginner chess players. "....but I didn't want to lose my queen." As much fun as queens can be on a chessboard, with their smooth exterior, their elegant round top with ever-so-subtle curves, IT IS JUST ANOTHER PIECE !
The best move on a chessboard, in any position, has to do with what is going to give you the biggest advantage. If that means trading queens off the board, so that you get closer to an endgame and you're already 2 or 3 pawns up, then by all means do it! If trading your queens means he doesn't get to castle, and will have a hard time protecting his king, then by all means do it. You should never avoid a move simply because you don't want to lose your queen, even when it means he'll lose his too. Chess can be just as much fun and exciting without a queen on the board.
Here are a couple examples of where queen exchanges are good!