For the 640 section, chapters 14-19 of the Active Directory Resource Kit should cover it. You should look for some resources on Read-Only DCs and use the links from the specific categories in the 640 sticky for more information. For the 642 section you may have to get more creative. You can always reference the sections in the 642 sticky, and there are some free downloads like TCP/IP Fundamentals and the Core Network Guide. I used the 642 Exam Cram as my primary resource when I took the 649 exam, but I also used Understanding IPv6 for an overview of IPv6. Be sure to do some labs on NAP (there is an entire book on NAP, but that would be overkill) and understand WSUS, and you should be good. Keep in mind that this is an upgrade exam. The base 642 objectives may include DHCP, but unless that has changed dramatically, don't expect any questions on it. MS assumes that because you have an MCSA that you already have these core skills. Focus on what has changed, be sure to cover any existing weak areas, and you will be fine.
xmalachi wrote: » I am using the MSPress book and CBT Nuggets for the 70-648 exam. So far they seem to be pretty adaquete. Here is a quote from Claymoore when I was discussing the exam with him: As far as I can tell, many of the practice questions are along the lines of what Claymoore has discussed.