I've done some YouTube work for LawTrades that has gotten a decent traction. We're still experimenting with it, but here's what I learned:

First step would be the make sure the video is actually engaging and most users finish watching it. This is important because the YouTube algorithm takes into consideration how many users actually finish watching the video then actually hit the "subscribe" button right after-- when that happens it tells YouTube/Google to rank your video higher.

Next you want to get some quality backlinks to the video, submit to social sites etc.. standard SEO practices.

Lastly, post it to your own blog with a transcript of the video-- you'll also want to be strategic with what words you use in the title, tags, and description.

Hope that helps to get your juices flowing on some YouTube marketing ideas! But at the end of the day each case is different and it really depends on your business, competition, and subject matter for what exactly you should do to rank your videos as high as possible in the shortest period of time -- feel free to give me a call to learn more.

R