Go to a college campus at the end of a semester.
Set up a table in a high student traffic area with a sign that says you buy college books. Having a good-looking sign and a cash box on your table will make you look more professional. Locations such as campus lawns, commons areas or student unions are good choices because these are often where students hang out. Check with the college's campus director for permission to set up your table. If you are not allowed to set your table up on campus, find a public space just off of, but right beside, campus to set up. An easy way to advertise your business is to have fliers made and pass them out to students--or even leave them lying on tables and chairs where students gather.
Purchase college books from students. Buy any subject as long the book is in good condition and is a new edition (old editions of textbooks quickly lose value). Research which book editions are still new and how much the local college bookstore pays for certain books so you can pay students a little more than your competition while still giving yourself a nice profit margin. You can compile lists of books that include the selling price of the book at the bookstore and what it sells for online so that you do not buy books that you will not profit from. Another option is buying a scanner that attaches to a PDA and allows you to scan book bar codes (see Resources below). Scanning the bar code allows the PDA to check the current price of the book online. Do this until you run out of money or you have acquired the maximum amount of books that you have storage space for.
Sign up for a seller account on an Internet book retailer (see Resources below). These accounts are usually free to set up. The company that owns the site usually takes a certain percentage of each book sale.
List your books on the site and begin selling.
Make fliers that advertise your bookstore and place them around your local college campus. This is especially effective right before each semester begins (when students are purchasing books for their classes).