That's a really, really, broad question. I can't give you a right answer, I don't know what you remember and don't remember from your masters' degree, and I couldn't answer all of those questions in one post if I tried.
However, since it's your first post, and since you can't learn the rules of the site without using it for a while, I'll try to help get you started.
For your car project, what you need to learn about right now is communication busses and automotive wiring. A Bus Pirate or other development board for automotive communications (Would ideally have CAN, the venerable Bus Pirate does not, sadly) will help you interface various modules in the car, and allow you to develop custom modules for your car if you need that. You'll need a DMM to check the voltage, current, and resistances between wires as you connect your wiring harness. A solderless breadboard will also be a good tool to quickly and easily prototype low-speed digital circuitry. However, you'll want a temperature-controlled soldering iron when it's time to actually build something. An oscilloscope and/or logic analyzer are also great to have, but they're quite expensive.
As far as websites go, this one is great! :) edaboard.com, ladyada.net, and adafruit.com are other popular sites, but there are far too many to list. You'll want to know a few distributor websites as well, like Digikey or Sparkfun from which to order your components and tools. I like the Circuit Cellar magazine, and I have a lot of books but it's hard to nail down a specific one that covers electronics in general.
I've never built a car, but I work at a company that builds electronics for cars, and I'm in a club converting a gasoline-engine car to a plug-in electric with my school. A number of us are in the automotive industry, and a lot of us like to work on our cars; not sure if anyone's built one. Most everything interfaces with a computer, and I've seen a lot of questions on household electronics and home automation. I'm sure you'll get plenty of good answers for questions in all of those departments here.
I hope that gets you started. When you have a better idea of what you think you want to do, feel free to ask for clarification and advice here. When you have a problem with something you're working on, that's what we're really here for.
A databook is a collection of datasheets, in printed book form, from a single manufacturer. Sometimes manufacturers would include application notes or white papers in the databook as well.
Back in "the day", engineers would have a large library of databooks. Around 1997 my library was made from six 6-foot bookshelves completely full of databooks-- that used all the wall space in the employee break room. Around the same time, manufacturer representatives and field-sales people from distributors would drive from customer to customer with their trunk full of databooks.
This was before the Internet was useful, and PDF's were commonplace. Databooks have been mostly obsoleted now, to the delight of field sales people and employees taking breaks everywhere.
Cookbooks are entirely different. They were almost always published by third parties, not the chip manufacturers themselves, and thus were mostly manufacturer agnostic. Cookbooks were more like application notes, while datasheets were more about formally documenting the manufacturers specifications.
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Considering you're of 'high school age', I think the MIT courses are maybe very difficult (from Mark's post) They generally require a lot of math and previous knowhow from highschool. Or am I only able to pick out the courses that handle circuit theory and maths?
You may find this very interesting:
http://www.allaboutcircuits.com/vol_1/index.html
Start at chapter 1 and read through. You may find some parts that you think is familiar, but read through it anyway. You may already know what a Volt and an Amp is, but it might also be nice to read through some literature so you can conform your previous knowledge.
This website is focussed on analog electronics. It's about understanding how electricity and electronic components work. This doesn't have a particular big focus on digital electronics, which you may want to know more about considering you're interested in writing computer programs.
As Mark said, Arduino is a great platform to start from for digital electronics. It contains a small microcontroller with an easy to pick up language to start with programming embedded systems. Out of the box you won't be that concerned with configuring registers of microcontrollers. You can get a ton of addons created by 'the community' for it. You can get a ton of stuff from Sparkfun.