So, you want to get SCJA certified, eh?
First thing you should do is take a look at the exam objectives. Reading the exam objectives, and knowing what you need to study is a good start, regardless of the exam you're working towards.
Next thing I'd say is you've got to start hacking out a little Java code. You don't need to be a Java expert, but you do need to know the syntax. I like the Beginning Java Programming for Dummies if you're a real novice, and then, Head First Java if you're a bit more advanced. Head First Java is more
SCJP focussed than it is SCJA focussed.
Then, I'd start nailing down the definitions of all the terms talked about in the client and server technologies sections of the Sun Certified Java Associates exam. Make sure you know what the abbreviations mean, and how the technology can be used. Going to the Sun technology pages, and even Wikipedia, is a good start.
You also need to know a little object oriented design and UML. I have a few sections in my SCJA Certification Guide that deal with OOA and OOD that have been getting pretty good feedback. It's definitely worth a look.
And as I just said, I do have a fairly popular book that covers all of the SCJA Objectives, which you can get to from my signature links. It's the best SCJA Study Guide on the market.
Also, you'll want to practice. I also have a book that's just dedicated to SCJA exam questions - over 350 of them in fact. The equivalent of 7 exams. I totally recommend it if you want to get in some good practice.
Best of luck on your studies. And good luck on your certification!
-Cameron McKenzie