WordPress MU

I have installed the Wordpress MU lastnight and I have configured and have the site up and running. My question is what is the best way to update the code base each night, do i simply copy the new files over my exisiting files and if so do i need to backup any of the files prior to uploading the new files and will this effect any of the site users and there blogs

See this topic.

I wouldn't update everynight unless you try it out on a test server or something. The nightly builds contain bleeding edge code and as you can tell from the changelog, often have bugs. Just a tip ;)

understood but on the days that I do update what is the best way to do it