From what I read in "Scrawny to Brawny", you want to figure out what your calorie needs are for a non-exercise day, and figure out what they are for an exercise day. Then, if you want to put on muscle mass, up that by about 250 calories at a time, with healthy stuff (whole grain rice, maybe a bit more protein, fish oil, omega 3 fats, etc). If you aren't seeing the growth that you want, add another 250 calories. Keep increasing until you see the growth that you want.
In theory, you don't want to lose weight; you want to lose fat, and gain muscle. What I found to be the most effective to do this, personally, was to focus on heavy compound lifts. Squats, deadlifts, and pullups (plus hang or power cleans and snatches) can help boost your testosterone, which in turn helps you pack on the muscles. Building up your legs (which have the largest muscles in your body) will also kick up your metabolism even higher, which will help you burn fat faster/easier.
As others have posted in other threads, it sounds easier to do one at a time, and once you've reached your goal, switch. I managed to put on lean muscle mass and take off fat just doing tons of extra hard lifting, so that might work for you also.