Give a few copies away to "networkers" who will spread the word about your book. Send copies to newspaper reporters (especially book reviewers and arts reporters), bloggers, teachers and people who love to read.
If you've written a children's book, call local schools, the library and daycare centers and ask to read your book to classes. If you've written a book for adults, hold readings at the library, bookstore and local events. Give away bookmarks that advertise your book.
Set up book signings at events that draw in lots of people. Look for literacy events at the mall, fairs, art festivals, holiday events, group signings with other authors and any event that relates to your book's topic.
Readers want to learn more about the author behind the work. Include your photo and bio in your book, on your website and in your promotional material. Set up a blog where you write about things related to your book. Network on MySpace and Facebook.
Advertise on the radio, in the newspaper or on local TV channels. Sponsor one of the radion station's events. Stations will sometimes announce book signings as well. Ask your local paper to write a story about you and your book.
Carry your business card, bookmarks and book copies with you, especially if you travel for business. Greet people and tell them about your book -- and provide a way for them to buy it.