PSP & PS3 Hacks Mods

Hi I am new to psp mods and hacks. I was curious though, I have a psp with version 3.80 firmware. If I wanted to downgrade to play iso's and homebrew games what version would I have to download to get my psp working to play them. Also what are the risks that I take. Like how much of a chance is there my psp will never work again? And how easy is it to downgrade and then play homebrew games?

You will need a Pandora battery + magic memory stick to mod your PSP. Since you have to use Pandora, there is no chance of bricking your PSP so that it will not work.