We recently had Kimberly Johnson come to our school and she was great! She did a workshop with students and also for parents during our PTA meeting. She is very enthusiastic! Visit her website for pricing. www.simplycreativeworks.com
or email her at This email address is being protected from spambots. You need JavaScript enabled to view it.
I just did a search on "children's authors" on Yahoo and found a site that had a listing for visiting authors. I think the suggestion about the library may be an even better idea, though!
Our school does an Author or Illustrator visit every year. Although I serve on the committee, I have not been a chairperson so I'm not sure how they get the person. I know that there is a list though, of authors that do school visits on a regular basis. I can find out in the next couple of days but I'm sure someone else on this board could help you faster. Just as a guess though, why don't you do a google search for a specific authors name and see what they have on their websites.