How do you monitor the temperature of your processor?

Solution
hardware monitor (cpu, gpu, hdd, mobo (if there were related sensor on it))
core temp (cpu)
speed fan (cpu and fan control utilities)
gpu-z (gpu)
For third-party programs, there is Speedfan, HWMonitor, and Coretemp. There is also AMD Overdrive, but that is kind of a different beast.

To put your CPU under load, and conveniently monitor temperatures, many people use Prime95.

Figuring out how to differentiate some of the different temperature sensors may take a bit of tinkering, and finesse. Good luck!