i've found the self-paced training kits to be a good starting point for preparing for exams. But it usually isn't the only resource you'll need. Next to the web resources (blogs etc.) there may be another book that might be of interest to you:
70-685: Windows 7 Enterprise Desktop Support Technician with Lab Manual (Microsoft Official Academic Course Series)
By Microsoft Official Academic Course
Do note that this book is also by Microsoft. I can't tell you how it differs from the self-paced training kit. It's the only other book about this exam I could find :)
Dimitri C. - Please mark the replies as answers if they help! Thanks.