Citrix has released some free technical how-to videos:

• Optimizing Printing in Presentation Server 4 environments
• Configuring Policies in Presentation Server 4
• Understanding and Designing Citrix Presentation Server 4 Farms
• Deep Dive into Citrix Presentation Server SpeedScreen Technologies
• Fundamentals of the Citrix Presentation Server Architecture
• Licensing Essentials
• Migrating your Microsoft Windows Terminal Servers to a Citrix Presentation Server Farm

Check them out here

[Via Virtrix - Virtual Tricks]