Below are links to cPanel/WHM Official User Guide
WebHost Manager® (WHM) User Guide
http://docs.cpanel.net/twiki/bin/view/AllDocumentation/WHMDocs/WebHome
cPanel User Guide
http://docs.cpanel.net/twiki/bin/view/AllDocumentation/CpanelDocs/WebHome
Please do not hesitate to contact technical support if you need any assistance with cPanel/WHM.