Conclusion
I would recommend allowing plenty of time to set this up. There are a lot of GPO settings here that you will need to test before going live with this. Allot a few days for installation and configuration of the Terminal Server, and perhaps as much as 2 weeks of testing time. Start by simply testing what your user session is like with both your personal domain account, and then also use the Domain Admin account. If you use a good majority of these settings, then even the Domain Admin account should be able to incur little damage through a Terminal Server session.

Resources
A good bit of research went into this guide. Information included here probably came from one of the following sources.

Windows Server 2003 Terminal Server Capacity and Scaling
Citrix MetaFrame and Microsoft Terminal Server Performance Optimization and Tuning Whitepaper at BrianMadden.com
The Ultimate Guide to Windows 2003 Terminal Server Licensing Whitepaper at BrianMadden.com
Terminal Server and Citrix MetaFrame Network Performance Troubleshooting (Part 1 of 2)
Terminal Server and Citrix MetaFrame Network Performance Troubleshooting (Part 2 of 2)
Locking Down Windows Server 2003 Terminal Server Sessions
Windows 2003 Terminal Server Part 1 at WindowsNetworking.com
Windows 2003 Terminal Server Part 2 at WindowsNetworking.com
Using Software Restriction Policies to Protect Against Unauthorized Software at Microsoft
Windows Server 2003 Terminal Server FAQ at Microsoft
Windows Server 2003 Client Access Licensing Overview at Microsoft
Windows Server 2003 Pricing and Licensing: Frequently Asked Questions at Microsoft
System Planning at Microsoft
Guidelines for Deploying Terminal Server
Windows Server 2003 Terminal Server Licensing Whitepaper at Microsoft
Configure Terminal Services Connections at Microsoft
Configure Session Directory settings at Microsoft