I'm not sure exactly what you're looking for, how your engine does things(I'm using a 2d engine), ect. I'm lucky enough to have a brother who's extremely skilled at Photoshop, which is very good for making graphics and even animating them, who creates sprites and 2d effects for me.
Photoshop 101 has a ton of tutorials, some good, some not so hot.
If you don't have Photoshop, which is understandable with it's price, there is also The Gimp which is a free tool comparable to Photoshop. Some even like it more, although brother and I do not.