What format is it in? You will probably want it in windows media or real player format so that people will be able to stream it. All you have to do is upload it like a picture, make a link to it, and you are all set up =)
Ohh I see.
Well what you are going to have to do is purchase a special video card and then install that in your computer. The absolute best card for this is the ATI All In Wonder.
Here is the link to the card on ATI's site: http://www.ati.com/products/pc/aiw128pro/index.html
If you go to http://www.pricewatch.com and search for "ATI All In Wonder" it will give you a list of the different prices (looks like it'll average somewhere around $100). There are also lower versions of this card that I'm sure will do the same thing, this is just the one I've heard most commonly so I linked that one.
This card has audio/video output/input so you can record them onto your computer, compress the video, and then be able to upload it.
Let me know if you need anymore help, there are lots of resources that will help you with this project.