Display SharePoint Users, Groups and Sites in a GridView and Use a DropDownList to filter the values

http://www.c-sharpcorner.com/uploadfile/hec.ravi/display-sharepoint-users-groups-and-sites-in-a-gridview-and-use-a-dropdownlist-to-filter-the-values/



http://msdn.microsoft.com/en-us/office365trainingcourse_lab_2_1_topic3.aspx