I have had pretty good success selling textbooks on eBay and also on Amazon. I sold 2 or 3 textbooks, and both times ended up selling them for almost the price I bought them for. Actually I think once I somehow made a net profit doing it. Just choose the price you want for it and let that bastard sit. Once September rolls around and college classes are starting up again, it's likely someone will buy it. Just don't be a scumbag and lie about the condition (happened with a used book I bought once, was pissed).