Took the 70-685 today and missed by one question (got a 68

. The printout after said I was weak on "Supporting Mobile Users" and "Identifying Cause of and Resolving Security Issues".
I have a book that claims to be for 70-685 and I've read it twice, but it does not go into much depth on wireless at all. Very skimpy in that department.

Is there a resource that goes over wireless in depth, from technologies 11b vs 11g to encryption and whole process of certificates for wireless/VPN users, what servers issue them and so on? I really need to hammer down that knowledge.

Bonus points for a similar resource for security issues.
Frankly the test asked a lot of questions about servers, which I thought didn't belong on a desktop test, but so be it.