Blotto, that's fantastic; have I invited you yet to be part of the Nexus member art gallery?
RayTracer, I'm totally self taught. My wife is a fairly hardcore photoshop user so we share our discoveries over the dinner table, which is helpful.
The pen tool is really essential. Most of it is just getting the hang of it. Keep your history palette open and if anything happens to your path that you can't seem to fix, just step back as many steps as you need to. Play with keys: command allows you to drag around and edit control points. Control allows you to change them from curved to corner and back. Also play with your Paths menu, see what it offers.
Keep making the great art, and those around you will eventually stop doubting it.