Bill English has done a nice job of describing the process of installing SharePoint 2007.

Here is the link

In case it looks like the site has been to quiet lately, don't worry, I am writing a new cheat sheet for SharePoint 2007. It will be finished when I know enough about the new version myself :-) I am also working on a major overhawl of the site, so watch this space!

The steps to upgrade from Beta 2 to the final release version (RTM) will be:

1. Apply the beta 2 Technical Refresh Patch
2. Uninstall SharePoint, I am guessing without deleting the databases.
3. Reinstall the final RTM version of SharePoint and reattach the databases.

Sounds a bit tricky, but it does mean that you could start deploying SharePoint now.

More info from Joel's blog here. One well worth keeping an eye on as it is full of very good information. Thanks Joel!