Choose healthy carbohydrates and protein foods, they will add calories without the fat. Protein such as chicken, turkey and egg whites. Good carbs like baked potatoes, brown rice and rice cakes.
It's crucial you eat enough carbs combined with protein if you want to build muscle. Protein shakes are good, add a banana for extra energy after your work out.
Grilled fish, with spinach and brown rice would be a typical meal plan.
Good luck :)