KoolZoid: Run your Dolphin.exe
Configure your graphics options (keep 'em simple for a first time run)
Set up your Gamecube controller (presumably you're using a gamepad or something)
Click the 'open' icon
Browse to your legally-acquired .iso and select it
You should see the game as an option in your Dolphin window now
Double-click the game
Enjoy.
JCD-Bionicman: Hey got it to work. I always wanted to play a game in slow motion! Kidding of course, I probably just need a new computer, it looks like all the settings are turned all the way down by default with the exception of dual cores option.
I can barely play it in this state but nevermind that. How would I set two input devices, in this case the w a s and d keys and the mouse as well, to both control the main stick?
You don't. For each gamepad configuration profile, one function of the gamecube controller is mapped to one input. However, should you find that some games you feel most comfortable using WASD to emulate the main stick, and some games you prefer using the mouse for it, you can create seperate controller profiles (there is a save/load profile option at the top of the Controller Configuration window) and then switch between them as you so choose.
As a caveat, though, I cannot reccommend using this emulator without a PC gamepad of some sort. Trying to emulate dual analogue stick inputs on a keyboard is no fun, and if it's no fun why would we do it? :)