A few that weren't mentioned that I've found useful:
Hammer (lite ball-peen and rubber) for minor persuasion (lite tap works really well on a wrench or socket that doesn't want to come off the fastener due to rust/grease)
Plyers esp. needle nose and regular (lineman I think their called)
Flare-Nut wrenches, specifically designed to work with tubing (aka brake lines and fuel lines) without crushing.
Picks, like dentist picks straight and bent. Don't pay more than $2.00 each, that's even high. So many uses ( removing grime you can't reach, feeling, etc) it's incredible, but be careful (of the part your working on and you, drop one on your thigh and it will hurt)
Diagnostic tools: timing light, dwell meter, compression guage, vacuum guage all useful, possibly borrow from a friend, or loaner from a auto-shop.
Volt meter - buy your own, you'll use it.
If you can afford it an Air Compressor, but your getting pricy.
You sound like me a few years ago, trying to learn how to do what with what. Something that I did was get catalogs, Sears, Snap-on, Eastwood Co, Harbor Freight, A&I, whatever. I'd look at the tools and try and figure out what they're for. And Why. Got me asking questions. These lead me to new questions and new answers. In short gained a better understanding of how things work, and (hopefully) avioded a few nasty "character building" experiences along the way. In short, every tool is build to fix a problem (exept for a few true rip-offs). Find out what the problem is, why it occurs and how to deal with it and you work that much smarter.
SprintCC