If you head over to the PSPU forums and ask how to work isos on your psp, your most problably gonna get flamed and called a noobish pirate(yea even if you dumped it yourself -.-). I suggest
www.pspcrazy.com for support.
but quick question... shouldn't you already know how to load a .iso if you dumped the game yourself?? The only way I know of dumping the UMD data is by using FastLoader and makeing a ISO out of the data that you dumped and it's even easier to run the iso then to make it yourself -.-"
anyways I almost forgot. What version psp do you have? If you have a 1.5 then your good.