The Book Report
Kids reads.com: The Time Warp Trio by Jon Scieszka
Scieszka and Smith share details of their lives and careers at this site. There's a bit of information about a number of their books, not just "The Time Warp Trio."
Scholastic
Scholastic: Jon Scieszka
The author shares some biographical facts here, and the site includes a book list, an interview transcript and a link to his personal site.