ok I am a total Mac newb so I need some help here. I have downloaded programs to install and they are in the dmg format but i cant seem to figure out how to install them to the laptops hd. when i double click on the dmg file it seems to create a disk image file and runs the program from that but doesnt install it to my hd for later use. how do I do this? also where do i add ram to ibook g3 700 i took the battery out but dont see any other doors on the bottom