I just passed my SCJA (OCA, JAVA SE5/6) last week with a 82% passing score. Not a shinning score to show off, but to a person who had no OOP experience before, I am quite happy with the score.
To recap, I used three books for this exam, and I think they are quite helpful.
1. SCJA study guide by Liguori and Finegan. [Very good, read book twice, did all the self test twice. The only gride is I wish they could cover a little bit more on chapter 11 and 12.]
2. Head First Java. Great book to understand Java in general.
3. SCJP study guide, not a must, but still recommend it for future study.
The self tests in SCJA study guide is good enough, but if you want to do more mock exam, I would highly recommend scja.de not because of its affordability comparing to Enthuware and Whizlabs, and its high quality and very close difficulty level to the real exam.
Now I have a question, if anyone else could help me out.
What is the correct path, in other words, what exams I should take next to be a real professional Java programmer/guru? I am thinking to take SCJP next, then SCJD. And something else (System Architect eventually in a manager level)