Installation Requirements for SharePoint 2010

SharePoint 2010 will only be available for 64 bit hardware. Microsoft's "minimum" requirements for RAM are 4GB for development/evaluation purposes and 8GB for production.

For an operating system, Windows Server 2008 SP2 or  R2. (Each have their own Hotfixes you will need).

Microsoft SQL 2005 or 2008 (specific Hotfixes, Cumulative Updates and/or Service Packs needed). That said, you will need SQL Server 2008 R2 for "Microsoft SQL Server 2008 R2 to work with PowerPivot workbooks".

The full requirements details are available here at this Microsoft Technet web page...

A video demo on "Installing SharePoint Server 2010" is also available on Technet.