It does in a simplified way. /assist works regardless of class. However, one must crawl before they can walk and the video is a good starting block since he's already got his multiplexer set up.

That video should work well -- but to answer his second question -- I'd suggest at least watching through the video first, then going on to the more advanced ordeal of matching up abilities that make sense together (for example: fireball and shadowbolt, healing and potting, mind flay and drain life)

If you want more specifics on running multiple roles (classes/specs) at the same time, I don't have a video for that -- but I do have an article: http://vboxing.net/v/tiki-read_article.php?articleId=23

The second article makes the assumption that you can read simple macros. If you're having trouble reading or understanding macros, you can take a look here: http://dual-boxing.com/wiki/index.php/Macros