I am trying to add all the sap related website links in one place. I will be keep on updating the links as i find new ones.
All SAP T-Codes : http://www.saptcodes.com/
SAP Help: http://help.sap.com/
SAP SDN: http://www.sdn.sap.com/
SAP Fans: http://www.sapfans.com/
Blog for most of the SAP modules: http://sapcrm-info.blogspot.com/ (thru header you can navigate to different modules).
http://sapdocs.info/ (this site has all the documetns and linked to all the useful sap sites).