To qualify for the Cardathon Challenge a book needs to meet one of the following criteria:
1) a book written by Orson Scott Card
2) a book edited/compiled by Orson Scott Card
3) a book with an introduction by Orson Scott Card
4) a book reviewed by Orson Scott Card on his official website.
No requirement on the number of books. Six to twelve are recommended.
Becky at Becky's Book Reviews has set up the challenge. The blog is Cardathon Challenge
MY TENTATIVE BOOK LIST TO CHOOSE FROM
Seventh Son (Alvin Maker)
Red Prophet (Tales of Alvin Maker, Book 2)
Rachel & Leah
The Folk of the Fringe
The Worthing Saga
I needed to linked them because I kept forgetting what each one was about.