It's easier than ever to get into electronics these days. Make Magazine (actually, O'Reilly) publishes a wide variety of books, including starter books on electronics and simple computer circuits. http://oreilly.com/
Also, Amazon sells some kits for folks who want to get their feet wet (tho wet feet aren't a very safe way to work in this field). This one is meant for teenagers who are probably younger than you are, but it will take you to the right part of Amazon: http://www.amazon.com/Vintage-Sports-Cards-MX-906-Electronic/dp/B00005K2SY/ref=sr_1_43?ie=UTF8&qid=1380830249&sr=8-43&keywords=electronics+kit
If you're working from a book rather than a kit, you can order parts, even in ones, from suppliers like Digikey.com For orders under $25, they charge an extra $5. Even so, they're much cheaper than Radio Shack. Also, look up Sparkfun Electronics and their collection of books, kits, and free online projects.
At the minimum, you'll need a multimeter (volts, amps, ohms). Check ebay for these. A soldering iron is a useful tool, but a cheap one can be more trouble than it's worth. Better to use a solderless prototyping board (see Amazon or Digikey) at first.