1. Use a test disc - follow instructions.
2. Buy hardware and software ... and spend the next year scrounging for information on how to calibrate TVs. You will get to a better image ... eventually.
3. Hire a professional.
4. Buy hardware and software ... and get professional level video training and you will get to a better image a lot faster than #2.
Three of these options will cost some money. Option 1 can be essentially free ... burn your own test disc.
Michael Chen @ The Laser Video Experience ISF/THX/TLV Video Instructor The Video Calibration Education Hub - www.TLVEXP.com
There is a PS3 thread that has a post that lists the best settings to use for the PS3... you should use those settings. I think it is the PS3 FAQ thread, but I'm not sure. There is another PS3 Owner's Thread, but I think they moved the settings to the FAQ thread because there were too many questions about PS3 settings.