I liked “Anybody’s Bike Book” – more on the friendly side than hardcore technical, but a great start, and covers most of what you need to start. Any good beginner bike repair book should go over tools (you can do a fair amount with just an adjustable monkey wrench, phillips and flat screwdrivers. If you don’t have them already, a good pump and tire irons. Then, if you want to get more into it, is allen wrenches, and maybe a chain tool. If you’re doing a lot of work, you’ll probably get tired of the adjustable wrench and get some fixed wrenches. You can do almost all you basic maintenance with those, except overhauling bearings, which need a few special tools depending on your particular bike).
There are some bike shops that give repair lessons, let you rent tools and space, or (best of both) will let you rent tools and the advice of a mechanic. Finding one of those is a great way to learn more advanced repair. (Are you in the Boston area?)
But as someone once told me, the great thing about bike mechanics is that you can just try stuff: nearly everything is right out where you can see it and figure out what it does, and nothing explodes or burns if you get it wrong. So go for it.