Links
Microsoft® SQL Server® 2008 R2 SP1 - Express Edition
http://www.microsoft.com/en-gb/download/details.aspx?id=26729
Microsoft® SQL Server® 2008 R2 SP2 - Express Edition
http://www.microsoft.com/en-gb/download/details.aspx?id=30438
http://www.sqlservercentral.com
http://www.sql-server-performance.com
http://social.msdn.microsoft.com/Forums/en/category/sqlserver