Use Windown Movie Maker. Comes with WinXP Pro automatically. Otherwise, download it for free from
http://www.microsoft.com website. You have to search for it on their website.
Learn how to use it.
Learn about free webhost such as google video, or utube.com.
Point is to use a video editing software. Then find a way to put it on the internet, whether a free way or a paid way.
I'm only giving you the general way of doing things.
Do a search on the bbs in the films section to learn more about film making and the process it takes.