Here is a list of all you need to know about Performance and capacity planning for SharePoint.
http://blogs.msdn.com/joelo/archive/2007/07/09/capacity-planning-key-links-and-info.aspx
Here is a good link that has some good info about exporting SharePoint List to SQL Server using SSIS.
http://blogs.officezealot.com/mtblog/archive/2008/06/03/importing-list-data-into-sql.aspx