1. Buy her book. Buy at least one book. Also, consider buying the book as gifts for birthdays, Christmas or other events. If you use your public library; request the book. Sometimes that's all it takes for the library to purchase a book.
2. Do not delay. The time to build up buzz is now. Buy it on Amazon.com or directly from the author. My authors make more money when you buy it directly from them. Your friend will be happy to find that people are purchasing her book.
3. Recommend the book. Write a review on Amazon.com. Share a note about it with the link to purchase on Facebook. Tweet about the book.
4. Tell you friend what you liked about the book. Did you learn something? Was it a good read? Did you read it in one night?
5. Suggest speaking engagements. Help them get an introduction to any groups with which you are connected: Rotary, Jaycees, Friends of the Library, etc.
7. Host a book party for your friend. Ask a couple of mutual friend to help with cookies and snacks and host up to 20 people. Your friend can read his book, sell and autograph copies.
8. Recommend your friend's website. If your friend does a blog post; tweet it or link to it.
9. Create a Wikipedia page for your friend. Authors cannot create their own page. The Wikipedia page should have a short bio, a bibliography, a link to the authors website.
10. Ask what else you can do. They may have ideas but did not want to bother you. Let them know that you are honored to help not bothered.
In another post, I'll give more ideas how you can help your author friend.