My main question is what is the best, current way to be able to play iso files of my games?

I bought a psp off of a friend and started looking around for ways to play backups of my games off of the memory card.
I have read LOTS of forums and am completely confused. I believe that the root of my confusion stems from reading outdated info.
The first thing I did was downgrade to version 1.5.
Then I used UMD Emulator V0.8C to try to play my iso.
I then ran across a lot of articles talking about homebrew applications ways to use them. I also ran across a devhook program.

At this point in time I am not sure if I should try to upgrade and then get a homebrew application or use devhook?? I just want to be able to enjoy my psp to the fullest. Any help at all would be much appreciated.