There are plenty of great resources on the Web. Here are some of our favorites:

• Overclockers.com's CPU Database
  Not a lot of downloadable programs, but the resource for overclocking.
• ArsTechnica.com
• Sharkyextreme.com
  Great for Celeron flip chip overclocking
• AnandTech
  Especially for Socket A AMD Athlon and Duron overclocking
• Tom's Hardware
• [H]ardOCP
• HMonitor, CPU-Z or Motherboard Monitor
  You've overclocked. How hot is your processor now? Is the fan still running?
  

To find your processor speed, have a look at CPU-Z.

Software that monitors your chip temperature, fans and provides other mobo info:

• HMonitor
• Motherboard Monitor
• ClockGen
  Overclock from within the operating system.

[H]ard|OCP has some great information for overclocking.

• Socket changes for AMD K8 CPUs
• Overclocking the Pentium 4 2.4C
• System Building Guide 0403
• ABIT KV8-MAX3 motherboard
• Asetek WaterChill
• Corsair Hydrocool 200
• VapoChill PE by Asetek