If you need help as to what to do after the YLOD you only have 3 options: Buy a new PS3, start the repair process through Sony (which means you will receive a refurbished PS3), or repair your PS3 through a 3rd party. There are a couple things you need to know for the repair process through Sony:
It will cost $150 plus applicable taxes for the repair if you are not in-warranty. (If you are in-warranty, the repair is free)
It usually takes approx. 1-3 weeks for the repair
You will most likely receive a refurbished (like new) console for the repair
Includes 90-day warranty
You will be unable to recover any saved files from your dead console unless you backed up the hard drive. However, all PS Store downloads are available through the PS Store for re-download. Also, all PSN activity (friends list, online multiplayer stats, etc.) are saved on servers and will be automatically recovered once you receive your new PS3.
Here's more: http://boardsus.playstation.com/t5/PlayStation-3-General/Unofficial-Yellow-Light-of-Death-YLOD-Informative-Still-Thread-R/m-p/40726489