Microsoft released Windows 2000 to manufacturing on December 15, 1999. It should be commercially available in February, but you could order now.
I can no longer find the 7MB Microsoft whitepaper on Getting Ready for Windows 2000 on their web site, so I have made it available here.
When you run the self-extracting executeable, it will create a Webfiles sub-folder. Double-click the tree.htm file to begin.
You may also want to visit http://www.microsoft.com/backoffice/basics/win2000sps.htm to learn what service packs are required for BackOffice products, prior to upgrading to Windows 2000.
Today, I have been preparing for W2k by connecting two new computers, moving my PDC, recabling, etc., so this is the only tip I have had time to write.