If you're wondering how to migrate your SharePoint databases to a new server, this Microsoft article is actually pretty useful, though still overly complex like most of their other articles.

http://technet.microsoft.com/en-us/library/cc512725.aspx

The one thing I would change is that they seem to recommend installing SQL Server Configuration Manager on web servers, when all that was needed in my case was to add an entry to the hosts file on the SharePoint web server that used the IP address of the new SQL Server with the name of the old SQL Server.  This might not be appropriate in cases where the old server is not being decommissioned.