Creating an AVI File

I'd like to create and add an AVI file to my website. Essentially it's an audio instruction file explaining how to perform a specific task. When complete, the "speech" will likely be a little over 5 minutes long. Am wondering what's the best method to create this? I was looking in things like Windows Media Player, Real Player, Roxio, etc and didn't specifically see how to create this file. Actually doesn't have to be an AVI format either, if a different format is better, can use that instead. Should I then post it as an AVI or better to convert to a wav or something else? The entire file will just be someone giving an audio speech containing nothing but words, no singing, music, etc, all words.

So my questions are, what software would you recommend? This probably will be a one time thing or at most less than a handful of times, so would prefer not to have to buy any software. Realplayer talked about doing this, but required the premium package.

Once I create the file, should I compress the file or convert to other format?

After that I'd assume just publish to website with a link to click on to start play back?

Any suggestions would be great!

Thanks!