Here is a list with my favorite websites around Remote Desktop Services and Virtualization:

Microsoft and Citrix

MSDN – Remote Desktop Services Team Blog

MSDN – Virtual PC Guy’s Weblog

TechNet – Ask the Performance Team

TechNet – Virtualization Team Blog

The Citrix Blog

Community Sites

Bink.nu, by Steven Bink

BrianMadden.com, by Brian Madden

CitrixTools.net, by Pierre Marmignon

DABCC.com, by Doug Brown

ShawnBass.com, by Shawn Bass

ThomasKoetzing.de, by Thomas Koetzing

TMurgent Technologies, by Tim Mangan

VanBragt.net, by Wilko von Bragt