Knight for a Bishop Exchanges
Here is something to think about. Exchanging a Knight for a Bishop usually has a profound effect on the game and the color complexes you should be seeking to forward your Initiative and play on. To get our minds thinking in the right direction, here are some general rules you can use.
Here we use the terms "Knight Side" and "Bishop Side" to denote the side that traded off that particular piece.
If you own the Knight, and you exchange it for an opponent's Bishop, then you will gain an advantage of the Initiative on the same color as the Bishop.
Ex.; Your N x wB = + White Initiative for "Knight Side".
This makes perfect sense as the opponent no longer has the Bishop of that color to defend with or play on that color squares.
If you own the Bishop, and you exchange it for an opponent's Knight, then you will gain an advantage of the Initiative on the opposite color of the Bishop. You should attempt to follow this exchange up with the trading off of the opponent's other Bishop.
Ex.; Your wB x N = + Black Initiative for the "Bishop Side".
This again makes perfect sense since you have traded off your bishop you will no longer have that bishop to defend with or play on those color squares.
These guidelines can often help you decide if you should be trading a minor piece or not.