The Official site - includes activities, online games and party ideas:

http://www.seussville.com/seussentennial/

The National Memorial Site to Dr. Seuss

http://www.catinthehat.org/

Craft ideas for Youngsters:

http://www.preschooleducation.com/seuss.shtml

More Lesson Ideas and Activities:

http://www.teachingheart.net/thedrsuesspage.html

A Great Variety of Resources and Activities:

http://www.education-world.com/a_curr/curr059.shtml

Collection of Ideas for many Grade Levels

http://www.thetimesnews.com/nie/activities_dr.suess.html

Lesson Plan for a One Week Unit on Dr. Seuss

http://www.pampetty.com/drseuss.htm

A Fun Collection of Ideas:

http://www.childfun.com/modules.php?name=News&file=article&sid=23

Using Dr. Seuss books to teach BIG ideas (peace, environment and more)

http://www.jalt.org/global/32Seuss.htm

An odd collection - a list of the Dr. Seuss Books and a list of the characters indexed to these books:

http://www.primate.wisc.edu/people/hamel/seuss.html

A Fun Set of Quizzes for you and Your Friends:

http://www.mea.org/design.cfm?p=3294