You can see how many blocks you've found with Deepbit under My Account/Advanced on the bottom.

If you're using Windows Check out: http://forum.bitcoin.org/index.php?topic=9982

I have EAH5850s and was not able to under clock under 500MHz with MSI Afterburner, but with Clocktweak I can under clock down to 175MHz.  I get 311Mh/s @ 825/175 and temps are between 55-59C.