For sound effects, backgrounds, tutorials on various products etc. some of these might be useful:-
http://freesound.iua.upf.edu/
http://www.motionloops.com/
http://www.detonationfilms.com/free_stuff.htm
http://edgen.com/music/news.html
http://phpbb.ulead.com.tw/EN/viewtopic.php?t=12931
http://www.istockphoto.com/file_search. ... erID=55035
http://www.doom9.org/index.html?/software2.htm
http://www.digital-auto.com/DTCsound.htm
http://www.devppl.com/tutorials/
http://forums.creativecow.net/index.html