If you've got the skills to pay the proverbial bills, it's a very good idea to offer a helping hand to musicians who may be looking to pick up some of the knowledge you've already attained. Magazines such as Computer Music are famous for getting artists to record tutorial videos, which drive traffic from Youtube. Rusko's Dubstep tutorial is one of my favourites (he's just such a likable dude), and as you can see the numerous links posted to this video and searches for "Dubstep tutorial" have taken this video to approaching 150,000 views. Can't argue with that.
"But I can't make Dubstep!". Well that's okay. The chances are if you've made music and you're looking to promote it, you have some skills in the world of music (If not, maybe try showcasing them anyway and it could turn into a comedy sensation). If your skills are in production, great, show people how to program a beat, or good EQ settings for guitars, anything you think people might search Youtube, or indeed Google for. If your skills lay in playing music, that's fine too, offer tutorials in how to play a popular song on piano, guitar, bass, or even drums. Be confident in your ability, and willing to throw it on out there for people's benefit.
There are three main reasons for offering tutorial style videos on Youtube. The first, quite obviously, is the ability to include links. Link in your description and it will drive traffic to wherever you want, Myspace, your own website, even Twitter. Another reason is simply getting your name out there, make sure you let everyone know who you are, and if they hear your name again they're more likely to start paying attention to your tunes. Thirdly, Youtube now offers financial incentives to those with accounts, and if you have enough followers you can apply for the right to earn money from the videos you chuck online, and every bit of cash you can make from music helps, as I'm sure you already know.