Author Illustrator Source
http://www.author-illustr-source.com/
A list of authors and illustrators who visit schools. There is a master alphabetical list of authors, or you can browse lists by region. A couple of clicks gets you to contact information. There are also pages that list author events around the country.

Ohio Children's Authors and Illustrators
http://www.oplin.org/page.php?Id=64-42-296-665&msg=
A list of Ohio authors and illustrators from Oplin and Oh! Teach. The names on the list link to lists of the author's (illustrator's) works, but offer no contact information.

Author & Illustrator Visits
http://www.tonibuzzeo.com/visitresources.html
Offers information on planning a successful author visit, including a Terrific Visit Tip Sheet and an Author Wish List Tip Sheet. Includes links to other sites with author information.

Scholastic Books -- Invite an Author
http://teacher.scholastic.com/products/tradebooks/inviteanauthor.htm
Offers advice on planning an author visit; also includes a list of authors and illustrators by region.