I've mentioned before that the book to prepare you to pass the DB2 9 Advanced DBA Exam 734 will be published early in 2008. If you are getting ready to take the exam now, here are a few ideas to help you prepare for the test.
Read the excellent book by Dwaine Snow and Tom Phan: Advanced DBA Certification Guide and Reference for DB2 UDB v8 for Linux, Unix and Windows. This book prepares people to pass the V8 Advanced DBA Exam 706.
Read the IBM DB2 9 New Features book to learn the new functions for DB2 9. I'd pay particular attention to the XML and Security sections. For this exam, I recommend that you gauge your readiness by taking the assessment exam.
I've had a few people in the Toronto Lab successfully pass Exam 734 using this strategy. Let me know how it works for you.