Here you will find resources related to Gmail for Google Apps.  If you have a resource to share, please submit it using this form.

Gmail Safety and Security for Schools - Resources related to Gmail security, rules, and filters for Google Apps
 Help guide - "Gmail Safety and Security for Schools" - Google Document link
 Sample Objectionable Word List - Google Document link
 Sample Student Gmail Guidelines - Google Document link
 Sample Student Gmail Safety Measures - Google Document link
 Training session video - Recorded February 11, 2013 - YouTube link

From Google - Official resources from Google
 Gmail: Basics - Website link
 Gmail: Advanced - Website link
 Gmail Help site - Website link
 Gmail Blog - Website link
 Gmail on G+ - Website link