Links

Exchange
The Exchange Team Blog
MS Exchange.org
Remote Connectivity Analyzer(also supports Office 365)
Exchange Server Deployment Assistant
MX toolbox
Exchange 2010 with Outlook 2003
Exchange 2010 SP2 Help File
Microsoft Exchange PST Capture Tool
Calendar Checking Tool for Outlook
Exchange downloads from Microsoft Download Center

Lync 2010

Technet Forum

Client Comparsion Table
Lync Powershell Blog
Help File
Resource Kit
Administration guide & power shell supplement