Just hit 100 thousand miles in my 98 SE. The water pump was replaced at about 90K and I just had a power steering hose replaced (430 dollars

should have had the whole power steering system replaced!) and its going to need a tranny rebuild (or not. some tell me it'll be fine).
What kind of things can I expect to encounter in the next year or so? Is there a thread that discusses high mileage contours?
Is a tune-up an easy enough task for some college student who changes his own oil and rotates his own tires? I'm kind of afraid to go to the dealer, simply because I want to pick out what goes in there when I get the tune-up done.
Any info much appreciated!