How to sell some books?

I have decided to put some energy into selling some of my writing.  I have never thought much about this so I am on the very early part of this learning curve.  Archway Publishing (the Simon & Schuster subsidiary that published my book "Walt") offers some interesting services in this regard and I have been very impressed and happy with them in the past.  Their services are very professional and are priced accordingly so I am inclined to climb up the learning curve a bit more before I invest thousands of dollars in anything.  I do subscribe to the Author's Learning Center, and I will devote some time to studying their information about marketing and publicity.  I'd love to hear from authors with suggestions for do-it-yourself book selling.