Passing the Exams
Whichever certification agency you choose, you'll need help and resources to pass the exams. There are a whole host of resources available, but here are some of my favorites:
Exam Cram Java 2 Sun Certified Java Programmer (Certification Insider Press, 1999), by Bill Brogden. This book takes you through each objective of the exam and provides tests at the end of each chapter.
Thinking in Java (Prentice Hall PTR, 2000, ISBN 0131002872) by Bruce Eckel, is an exceptional booknot least because you can download it for free from Bruce's web site! You can also purchase a very good CD-ROM seminar containing talking tutorials based on the book's contents.
Of course, Sun's Java web site is a very useful source of information. You can download lots of software to help you in your quest (including the Java Development Kit, etc.), plus check out a number of good tutorials. There's also an extensive list of courses and companies that run them, available on the Sun training web site.
A number of amateur sites offer practice exams, some of which are available via the Java Certification web ring (but watch for annoying pop-ups).
For those interested in the more advanced Java topicsfor example, architecture issues such as J2EE, EJB and JavaServer Pages (JSP)I suggest visiting TheServerSide.com, which, as its name suggests, is a wealth of information about all things server-side.
There are many discussion forums and Yahoo! groups for people preparing to take Java certification, but they change so often that I suggest you use a search engine to find those.