download mp3s on your computer in the MY MUSIC folder or something

then plug in the psp via usb cable

then wait until a folder pop ups and clik on open or veiw files

then clik ur way to the MUSIC folder and just drag and drop the mp3s from your computer folder to the psp MUSIC folder

u might want 2 drag the window size of the folder u put ur mp3s and the psp music folder so both fits on ur computer screen and just drag the mp3 u want 2 the psp music folder

if u dont have a MUSIC folder format ur memory card