You can print the exam objectives from sun's website.
I am using the book "Head First Servlets & JSP" written by Kathy Sierra, Bert Bates and Bryan Basham. I have not read any other book for Servlets & JSP yet, so I cannot recommend/comment on any other book.
The HFSJ book is good. I like it very much. You can buy it for less than US $30 at Amazon.com(qualifies for free shipping).
You just have to concentrate and study deeply. You should also have the "Servlet & JSP" API and specs and use them for exam preparation.
The exam covers the following specs:
Servlets 2.4 JSP 2.0 JSTL 1.1
You can find the links to download these in the SCWCD Links section.
Hope this helps. Good Luck!
[ January 13, 2006: Message edited by: K Bala ] [ January 13, 2006: Message edited by: K Bala ]