try
http://www.airbrush.com this is a good site lots of tips and boards to post questions on.
The flames are not to hard to do but it depends on the type you want. Ghost flames are easy, tribal and the more complex are harder to do. the wosrt is the layout getting them to look right the shading is the easy part. I lay them out on roll paper the exact size I want them when I do them. then I just transfer the pattern to clear contact paper and cut it out stick on and spray the base color and then shade them in really not that hard.