There are the usual suspects already mentioned, but maybe even better would be the same things, only used. Then you'll have even more justification for experimenting. I mean, if the frets are already a mess, you won't feel so bad if your first attempt to level/crown/dress them returns less than stellar results. Same with pickups, nuts, tuners, truss rod adjustments, etc. You have nowhere to go but up. A little positive reinforcement is a great motivation to continue.
Also, especially as it concerns fretwork, be aware that everybody and their brother has a guitar/bass laying around the back of the closet, under the bed, in the attic/basement, etc. that's nearly unplayable for one reason or another. You can gain a lot of knowledge and experience not only with how things are done, but what tools work best. As an added bonus, you gain Brownie Points from friends and relatives for returning instruments to service, even if it's just to sell them for beer money or give them away to a budding young SRV or Joe Satriani.
