The Exchange UE team has released some additional documents based on the Exchange Server 2007 help file…
Configuring Permissions in Exchange Server 2007
http://www.microsoft.com/downloads/details.aspx?FamilyId=8F74D1F7-3B50-42BA-8431-33DAA72A8A25&displaylang=en
Operations Management and Monitoring of an Exchange Server 2007 Organization
http://www.microsoft.com/downloads/details.aspx?FamilyID=e96604b1-5332-4c4e-a0a6-2c85216147a0&DisplayLang=en
Managing Mailbox Features in Exchange Server 2007
http://www.microsoft.com/downloads/details.aspx?FamilyId=87332ECE-5F95-45FE-9554-70C2F8D38408&displaylang=en
Management Interfaces in Exchange Server 2007
http://www.microsoft.com/downloads/details.aspx?FamilyId=085BB55C-EF90-4BB1-95E9-70D63941EF1B&displaylang=en
Technical Architecture of Exchange Server 2007
http://www.microsoft.com/downloads/details.aspx?FamilyId=B34FA7CC-8F13-4E21-AE87-EB824728DDD1&displaylang=en
Exchange Server 2007 Planning
http://www.microsoft.com/downloads/details.aspx?FamilyId=1A6EFDD6-D80E-489D-9A1D-8F3E01BAA3C5&displaylang=en