Some sites that I find:

www.q3radiant.com
*Some tutorials about qe/gtkradiant

www.valve-erc.com
*The center of halflife editing

www.inside3d.com
*Find Qukec info here

www.q3center.com
*Here I find some tutorails on Q3 coding.

http://www.planethalflife.com/commu...ed/editing.shtm
*Have a search here

http://www.planetquake.com/code3arena
*Another good site about q3 coding

http://www.planetquake.com/q3radiant/
*Another good site on q3 map editing

http://www.planetquake.com/QuakeLab
*Come in the newbies,when you learn all you''ll be experinced ones

http://www.planetquake.com/jitspoe/
*About q3 editing

http://www.qmap.org
*The home of quake1/2/3 mod/map developers

http://www.planetquake.com/temshamblers
*The infamous quake1 sp maps review site.

http://www.tenfourmaps.com
*The most famous sp level review site ever.

http://www.gamedev.net/reference/ar...article1738.asp
http://www.gamedev.net/reference/ar...article1739.asp
*An article on Level Design.

http://nwn.bioware.com/forums/
*If you''re interested on NWN modding,come here.

http://www.planetcnc.com/ra2mod
http://www.deezire.net
http://www.federationstudios.net
*3 sites on C&C2/RA2 editing.

http://www.leveldesigner.com/
*Mainly focused on Unreal/UT/UT2003 editing.

http://www.shrak.com/tcpage/tcschool.html
*"Total Conversion School",written by the authors of Shrak,the 1st total conversion of Quake1.

www.d2mods.com
*Center of diablo2 modding.

http://www.planetunreal.com/archite...irst_level.html
*Some newbie tutorials on Ued3.0