Where to start? Well the best way is to just go out and work on your car. Need the oil changed? Change it yourself. Spark plugs? Go buy a spark plug socket and get to work. Head gasket goes out? Well you'll need a torque wrench. Between owners manuals, shop manuals, and factory service manuals, not to mention the countless number of tutorials and videos on the internet, you can become an incredibly proficient shade-tree mechanic pretty quickly.
For tools, it depends on your budget. If money is of no object call up a Snap On truck guy and ask him to stop by your house, but have plenty of credit cards lined up
But really, if you're willing to spend some decent money, go to a Sears and buy a Craftsman mechanic tool set. Should have about 100 different tools of decent quality (Craftsman isn't at all what they used to be, but it's still decent quality tools). This will help you get started.
If you don't want to spend that kind of money, look up Harbor Freight, they are a discount tool supply company. Lots of cool stuff, but the quality - at absolute best - is "acceptable". But they are really cheap, and you can get a basic mechanics tool set for like $50.
Either way, now you have a basic tool set. That should get you going for 90% of the projects you'll do in your drive way. For the other handful that you need specific tools, you can buy those as you go and need them. One of the ones I recommend buying soon, and investing in a good quality tool (at least Sears, not Harbor Freight) is a torque wrench.
So now you have some tools, and you can look up the basics of changing oil and filters on the internet (because those things are pretty common in concept across all cars) but now you want to do something a little more involved. Depending on the car you have, maybe you need to redo a timing belt. You're going to want a repair or service manual. Now repair manuals are typically by Cymer or Haynes, they're books about 1 inch thick. I'm not personally a huge fan of them, because they tend to be somewhat vague and without details. So if you can afford it, you're going to want the factory service manual. By comparison, these are usually multiple 2-3 inch thick books. LOTS of more information. You can sometimes find them on eBay.
Woo! You're making good progress, you're no stranger to an engine bay and you even helped your friend pull his engine last summer. That's great! But now you want to do something more. You've always been a huge fan of those older cars, and your neighbor is selling a cool one that just needs a bit of work (he says - it will ALWAYS need more work). So you buy it, and find some rust in the rear fender well. Time to go buy a welder! You're going to want a MIG welder. It's basic, but it's very easy to use, and will work for the majority of simple tasks. Look up some more guides! There's tons of welding videos on the internet, and you can become a reasonably proficient beginner welder just from watching videos and practicing a bit.
Sorry, ranted a bit
The point is: Buy some basic tools, and a service manual for your car, and go out and work on it! You'll learn as you go, and can build up quite the toolbox over a few years. It's a lot of fun, I love working on my own cars, and you save a ton of money when you can change your own oil, do your brakes, etc.