What are the legalities surrounding usage of this though? I have never really understood it. So I legally need to own the game, but I still need to "download" a ISO copy to feed it into the emulator?
From my limited knowledge of Dolphin, you must own the game and "rip" the ISO off the disk using a software tool, sort of like ripping audio off a CD. Then you load point the emulator where the file is and that allows you to play the game.
Yes, that's how everyone does it. Especially people interested in emulators who totally own the console and the games the emulator is attempting to emulate.
What are the legalities surrounding usage of this though? I have never really understood it. So I legally need to own the game, but I still need to "download" a ISO copy to feed it into the emulator?
Then its as I expected. Of course its still legal to "download" the pre ripped ISO provided you own the original already. Considering disc drives are not so common place in the pc community now outside of laptops and such.