This is the site I mentioned in the breakout that offers the best sample questions for the SCJP exam I've found.

Each day they publish one question for free:

http://www.examulator.com/phezam/question.php

It's a good habit to visit the site each day and try the question, I still do it to this day.

From this next page, you can take a free 60 question practice exam or pay the $15 dollars to have access to about 350 test questions, well worth the price as a test preparation tool.

http://www.examulator.com/home/tigertamer.htm

One caution - There's not a lot of value into diving into these questions without studying, you'll probably get discouraged and angry at being tripped up by little details. Large amounts of practice questions are best used near the end of your study regimen to identify gaps in your knowledge, and prepare you to answer questions quickly and accurately. However, if you pay the fee, you can select questions from a certain topic, like "Collections and Generics". It could be very useful to try those questions right after studying that material, to help cement your understanding (Similar to the end-of-chapter questions in the book).

Please note - I get no kickbacks from this site (But not because of any personal integrity, they just haven't offered), I just like their questions