Congrats on your new PC, very nice choices on parts, my friend built an i3 gaming system a few weeks ago, runs great.
Aida 64 (info+ temps of everything) (this one isnt free. that is, to buy.)
GPU-Z (gpu info as well as temps)
Prime95 (Cpu stress test)
3dMark (Cpu+gpu stress test)
furmark (gpu stress test)
CPU-z (info but no temps for cpu)