Other than virtualization, Citrix/terminal services are the most common projecta I have been working on recently. The following are taken from bookmarks and notes that I have kept in several places. I hope they are helpful!

Tuning Citrix Presentation Server on VMware ESX from The Ether

Citrix on VMware, 1vCPU or 2vCPU ? from Alan Renouf

VMware: Best practices for deploying Citrix on ESX From Virtrix

Personal folder files are unsupported over a LAN or over a WAN link PST files are not supported on networks!

A .pst file is a file-access-driven method of message storage. File-access-driven means that the computer uses special file access commands that the operating system provides to read and write data to the file.

This is not efficient on WAN or LAN links because WAN/LAN links use network-access-driven methods, commands the operating system provides to send data to or receive from another networked computer. If there is a remote .pst (over a network link), Microsoft Outlook tries to use the file commands to read from the file or write to the file, but the operating system then has to send those commands over the network because the file is not on the local computer. This creates a great deal of overhead and increases the time it takes to read and write to the file. Additionally, the use a .pst file over a network connection may result in a corrupted .pst file if the connection degrades or fails.

Network Stored PST files … don’t do it! From the Windows Performance Team
You may experience performance problems when you are working with items in a large .pst file or in a large .ost file in Outlook 2007
Lessons Learned While Deploying Citrix Presentation Server 4.5 in a Virtual Datacenter VMworld 2008 Session

UPHClean and other profile ramblings Technet Blog

Optimising and Troubleshooting Logon Time to the Server

How to customize Office for Terminal Services

Performance impact of Office 2007 on Citrix servers

How to change the company name and user name in Office 2003

How to turn off the speech recognition and handwriting recognition features in Office XP

How to Effectively Troubleshoot Application Integration Issues
Microsoft Office 2007 Known Issues
The Language Bar Icon Appears in the Notification Area After Launching a Published Application
Antivirus Software Configuration Guidelines for Access Essentials/XenApp
Key Infrastructure Server Tuning
Configuring TCP KeepAlive Values to Improve WAN Links and ICA KeepAlives to Place ICA Session in a Disconnected State

Citrix Support Hotfixes