GNU/Linux Related :

www.linuxgazette.com, www.linuxjournal.com, www.linuxplanet.com

Microsoft Related : www.codeproject.com, http://msdn.microsoft.com

Project Hosting : http://sourceforge.net, http://freshmeat.net

Forums : www.linuxquestions.org (GNU/Linux), www.experts-exchange.com (all technologies), www.pagalguy.com (CAT and general interests)