Q6600 OC voltage question

So I have been tinkering with my Q6600 (B3 stepping =( ) and decided to overclock it a bit since I have been hearing how easy it is to overclock it to 3.0Ghz. I didn't want to jump to 3.0Ghz right away since I am new to OC'ing so I OC'd it to 2.6Ghz leaving my MB to auto set the voltage for "optimal settings". When I loaded up Windows my CPU temps were in the high 60C's and the voltage was set to 1.34v. That didnt seem right at all to me, so I lowered the voltage in the BIOS to about 1.17v and my temps dropped by 22C! I don't know much of anything about the voltage and what effect it has on OC'ing so I was wondering if one of you can help me out? Is it safe to run my CPU @ 2.6Ghz using the voltage I set? Can I get my CPU up to 3.0Ghz with that voltage or will I have to increase it? I have an Artic Freezer Pro 7 with A5 Silver as my colling source. Any help would be nice.

What program should I use to run the CPU load test?