Share 'White balance adjustments'

For some reason, since using the DSLR, most of my pictures turn out too light / bright. That is really bugging me. I've tried to play with the modi on the camera (like pre setting for shadow, sunlight, electric light, etc.) It works a bit better, but I guess I would have to use the white balance adjustment right then and there. But how? Where? :) With most cameras you can adjust the white bal...