Well, since no one else has chimed in, I guess I'll jump in with the parts list.
Essentially, you should replace the seal (you need this anyway), the nitrogen bladder, the oil (I know, obvious, but thought I would list anyway), and the Schrader valve. Except for the valve and shims (for shock tuning only), that's about all you should ever have to replace. However, while you have the shock apart, check and make sure the shock rod is not bent. This happens, and can make the seal go bad. If it is bent, it can be fixed by a good machine shop, so don't despair. The seal and bladder should be available through White Brothers or Race Tech for $50-$75, but I use only BelRay 10wt suspension fluid when I rebuild my shocks.
Post up any questions during your rebuild. Good Luck.
Rick