First of all welcome to PS3news
. To hack or "mod" your PS3 to run homebrew and game backups you will need to be on 3.55 firmware or less. If your firmware is higher than that you can use a mod-chip such as the E3 flasher or Infectus to downgrade your console, though it's not easy and may require some soldering.
If you are however on 3.55 firmware (or less) you can install a CFW (of your choosing). Here is a "noobs" guide on everything you need to know about CFW (http://www.ps3news.com/forums/ps3-cf...de-118615.html
). I suggest you install KMEAW 3.55 CFW to start of with (download from here - http://www.ps3news.com/forums/ps3-cf...ry-118021.html
) and you can then move to another CFW if you choose to do so.