Would I be too smug to suggest my own book? ExamScam Certification Guide for WebSphere Portal 5.1. It's available on Amazon.
I've got two small sample quizzes on my website, and a few multimedia tutorials as well. Please check them out:
http://www.technicalfacilitation.com/examscam/get.php?link=../scja/testsall The
test is very JSR-168 heavy. I was surprised at the lack of old IBM Jetspeed stuff.
Good luck, dude.
-Cameron