I'm not going to list the specific steps that I used to buy my textbooks; you can find that in an earlier post. I'm also not going to list the books I bought; the prices won't matter in 6 months.
Also, I strongly urge you to do your own comparison shopping; don't just take my word for it.
But I will discuss some of the things I've learned in the past few days.
First, digital textbooks simply cost too much, and renting the ebook wasn't an option for any of the books I needed. The ebook prices looked good compared to list price, but the honeymoon ended when I matched them against the used price. With one exception, the used price was far lower than the ebook price that I found on Inkmesh. And that one exception still cost more than the used price, but only by about a dollar.
Next, rental prices might look good in the college bookstore, but when you go to a comparison site like allbookstores.com you will see that the used prices can get a lot cheaper than you might expect. Of the 6 books I need, the used price was often less than the best rental price. Even when renting presented a cheaper option, a used book was often less than a couple bucks more than the rental price.
And guess what? That price is strictly the out of pocket cost. While a rented textbook has to be given up at the end of the semester, the used book can probably be sold again. In the long run the used book will cost you less.
So at this point I have just found that all the hype about how renting saves you money, or how ebooks save you money, or that renting an ebook saves you money, is exactly that.
I predict that used books will continue to be the best value going forward, and I think they will stay that way unless and until open source textbooks become popular. They have all of the benefit and none of the cost.