From FCP Export QuickTime Movie. You can create a self-contained if you like. Import that file into Compressor. Use Web Streaming or Web Download QuickTime 7 Compatible setting. There are several choices there. I use H.264 300kbs. Then export.
Windows users will need the latest version of QuickTime on their system in order to view the file.
The two other fiile formats that work well for the web are Flash and WMV.
Steve Eisen
Eisen Video Productions
Director-At-Large
Chicago Final Cut Pro Users Group