First question, what firmware are you running?
Quick run down of what goes where for you to refer to...
Emulators and homebrew applications go into your GAME150 folder
Playstation games go in your GAME folder
ISO/CSO files go in your ISO folder
I havent used the brewpacks before but i believe they're all homebrew so you would place them into your GAME150 folder.
For further details on loading homebrew and other files you can refer to my starters guide...
http://pspbrew.com/forum/viewtopic.php?t=9454