For CPU/mem subsystem stress testing, I've come to love IntelBurnTest (http://www.xgamingstudio.com/forum/showthread.php?9-RELEASE-IntelBurnTest-v2.52
). I mainly use it to test OCing stability, and for new, stock builds. Despite the name, it can pretty much work on any modern platform released in the past couple of years, AMDs included. A quick test can raise temps by at least a good 10° C or more from idle, depending on your system's cooling capability, more if you used heftier test settings.
For graphics, I agree with others here, Furmark (http://www.makeuseof.com/tag/test-graphics-card-stability-furmark-gaming/
) can be a good test as well. Just make sure you've got good cooling and a decent PSU capable of sustaining your vidcard's load needs.