Send a letter to the author in care of her publisher. You can find publisher contact information in the front of the author's book or on the publisher's website.
Visit the author's website. An author usually posts a contact email address on his website. If you're not sure if the author has a website, look up his name online to find out.
Log onto the author's message board, if one exists. Some authors happily chat with the public on blogs and message boards. At least you might find someone on the message board who knows how to contact the author.
Write to the author's agent. Agents forward correspondence to the author. Always be professional and clearly state your intentions for contacting the author in your letter.
Find out if the author is doing a book signing at a local bookstore or appearing at a convention or writer's conference in your area. Make plans to attend the event and approach the author, if possible.