There isn't an exact guide for it, due to this form of dual boxing being the most difficult. Performance is an issue, as well as response times for micro management.

The best solution I can give is Auto Hot Key which sends a keystroke to both instances.
http://www.dual-boxing.com/forums2/viewtopic.php?t=17

For running WoW on the same PC simply just double click your WoW icon twice. Play in windowed mode and turn off your in game sound it will increase your FPS by a good 50%.