Hi,
The Microsoft prep book for 70-536 comes with two long erratas and I have seen other users say it covers only 75 percent of the exam so you can add the book in the third link to your study material for exam 70-536 VB.NET.
http://support.microsoft.com/kb/923018
http://support.microsoft.com/kb/935218
http://www.amazon.com/Programming-Microsoft-Visual-Basic-2005/dp/0735621837/ref=pd_sim_b_2
In exam 70-528 most of the online reviews says the Microsoft prep book is enough to pass the test and you could buy the Stephen Walther's book to improve your score on the exam.
http://www.amazon.com/MCTS-Self-Paced-Training-Exam-70-528/dp/0735623341/ref=sr_11_1/105-6889028-2056438?ie=UTF8&qid=1181190174&sr=11-1
http://www.amazon.com/ASP-NET-2-0-Unleashed-Stephen-Walther/dp/0672328232
So buy two books for each exam when you have read the books you also need good practice exam before you take the tests. I have passed both exams but in C# and not VB.NET.
Asp.net MVP, MCPD Web C#, MCITP BI & MCTS SQL Server 2005