If you believe that the truly educated never graduate, then I'm still a student. Certainly, I read a lot. And my interests are sufficiently eclectic (and my patience sufficiently short) that even the library at Greenback won't fill my needs.
Still, a lot of the books I'm interested in are (or have been) used as teaching texts. And if I'm reading for my own purposes, I don't need the latest edition. So, I buy used. And cheap. Which usually means online.
Typically, I'll go to Amazon or Barnes & Noble to search on the title, then paste the ISBN into my Google search box and hit "start". There are a couple of book search services/market listing places (abebooks, alibris, a couple more) that commonly pop up, and I almost always find what I'm looking for at a price I'm willing to pay. (As I said before, cheap.)
But I've got a new favorite online bookseller. As it happens, I bought stuff from them in the past, but never directly -- always through one of those front-end services mentioned earlier. Now I'll go there directly first, and look elsewhere only when they don't have what I want at a price that's ... well ... you know.
Better World Books. That's a plug. I don't own stock in them, and I don't know who does. I'm not a compensated endorser. I just like their business model.
Go to their site, and you'll notice a couple of things. First off, they (currently) claim to have raised over five million dollars for global literacy. And to have kept almost 17 million books out of landfills. Now, that second figure might be something of an overstatement, as many of the books referenced probably had other places to go before ending up in the landfill, and there's no guarantee that just because they went to one more owner they won't eventually end up underground.
But the $5,000,000+ is presumably accurate. I just bought a handful of books on various subjects, and each item in my online shopping cart was labeled with the name of a literacy-related charity. Presumably, some portion of the funds I transferred went to those good causes.
Additionally, while betterworld offers free shipping within the US (unless you're really in a hurry), it does impose a small fee. To offset the carbon dioxide emitted as a result of transporting the package. My fee was sixteen cents. Even on an administrator's salary, I can probably afford that.
So they're selling used books (which is, to my mind, an inherently noble calling). And they're raising money to promote literacy worldwide. And they're inducing their customers to offset greenhouse gas emissions.
Now I know what I want to do when I grow up.