First off, I'm not asking HOW to do these things, because this board is already filled with tutorials. I just don't know where to get started and what order I should do things in.

I've got my hands on a version 2.5 or 2.6 psp (not sure atm, a new screen is on the way, got this for free). I downloaded a version 2.71 update, and the easy 2.71->1.5 downgrader. As far as I know this isn't going to require any GTA or other games. From here, I'm kinda lost. I know I should get custom firmware, but there's just so much out there, I have no clue where to get started. Just a list of things I should do would help me greatly. Thank you in advance.