Local libraries are always my favorite. They’re completely free and a great way to find other book freaks.
OpenLibrary.org: a completely free resource that helps you find what books are at libraries near you AND allows you to download classics and some newer popular books to your computer or portable device.
Goodreads.com. You can’t actually read or buy books on it, but you’ll find a lot of suggestions, especially if you sign up for the monthly newletter. It’s also a great way to keep track of the books you want to read in one convenient place. Also, it’s free. We love free things.
Yard sales sometimes sell gems for a song. Best find I’ve had: Carrie. Without that copy — which I got for 50 cents — I wouldn’t have continued with King.
I’m a fan of e-readers. I get to carry a little library around with me. Personally, I’d go for the paper-white versions (usually the older, less-tablety editions) of Nook or Kindle. The screen is easy to read on indoors and outside, and you almost never need to charge them. Also, downloading an e-book is usually about five dollars cheaper than buying a physical copy.
I also am a fan of meeting with people at bookstores — we now have a Books a Million in my town. You save calories by not reconnecting over meals (though I can never stop myself from buying some tea. Every time) and it’s very hard not to walk out with a new book (which, you know, is a buy for your brain.) All the links I have are to Barnes & Noble only because I’ve always used them. But supporting small bookstores, if you’re lucky to have one near you, gives you extra special brownie points.