I've recently become interested in building a barebones PC to replace my aging HP Pavilion. I found the following resources useful—and you might, as well:
- Build Your Own Mini-PC For The Office
- Lockergnomes Forums: Barebones System
- PC vs Console: Good place to custom build a computer?
- ExpertsExchange: Building a barebones system
- Acme.com: Build a PC
- Ars Technica System Guide