Links: SharePoint 4.0 Service Pack 1

SharePoint Foundation 2010

KB 2460058: Description of SharePoint Foundation 2010 SP1
http://support.microsoft.com/kb/2460058

White paper: Service Pack 1 for SharePoint Foundation 2010
http://technet.microsoft.com/library/hh301732(office.14).aspx

SharePoint Server 2010

KB 2460045: Description of SharePoint Server 2010 SP1
http://support.microsoft.com/kb/2460045

White paper: Service Pack 1 for SharePoint Server 2010
http://technet.microsoft.com/library/hh285676(office.14).aspx


Related Links

Known issues when you install Office 2010 SP1 and SharePoint 2010 SP1
http://support.microsoft.com/kb/2532126

List of all SharePoint 2010 and Office Server 2010 SP1 packages
http://support.microsoft.com/kb/2510766

Microsoft SharePoint Server 2010 June 2011 Cumulative Update
http://support.microsoft.com/hotfix/KBHotfix.aspx?kbnum=2536599

Update Center for Microsoft Office, Office Servers, and Related Products
http://technet.microsoft.com/en-us/office/ee748587.aspx

Updates for SharePoint 2010 Products
http://technet.microsoft.com/en-us/sharepoint/ff800847.aspx