The only real method I've ever known when it comes to paper mache is with using liquid starch(the kind in the bottle, not the spraycan). Easiest point to start is along the outside(at least that is where I began), then once you are satisfied with it, begin on the inside(unless you decide to slush-cast the inside instead of fiber-glassing/paper mache).
I haven't begun to work on the inside yet, but I will try to get a picture up to show how its coming along so far. And I do plan on using bondo on the outside, as well.