If you participated in National Novel Writing Month (NaNoWriMo) and have your first book under your belt or publishing a novel is on your New Year Resolution list, there's lots of information out there to help you get started with publishing and marketing.
Here are a few links I've found:
If your book is edited and ready to go, check out Smashwords Style Guide to see how to format an e-book.
Russell Blake has a wealth of information on how to market your book.
Offer free books to boost sales of your other novels. (This suggestion from Karen Woodard works great if the book is part of a series).
Tips and tricks to Improve Sales by Lindsay Buroker
13 Steps to write a 25 page e-book in 13 hours
Self Publishing Success Stories
J.A. Konrath - Suggestions for E-Book Promotion
Book Covers - interview with Chris Howard