Useful links. Pretty much all of the sites I use and referred to in the tutorial for all things modeling
Reference/Artists
The best online character reference resource by far : http://www.3d.sk
Impressive research on character setup : http://staff.ci.qut.edu.au/~barkerc/Final%20PAN%20website/charactersetup.htm
Bay Raitt, character artist extraordinairre : http://cube.phlatt.net/home/spiraloid/
Stephen Stahlberg, particularly adept with the female form and several very useful tutorials here too : http://www.optidigit.com/stevens/
Vance Hartwell, sculptor. Awesome skin painting ideas : http://www.themonsterlab.com/vance-skinpainting.html
Tools
Out of the box, Maya lacks tools for quickly selecting edge loops which makes things time consuming. However, thanks to the beauty of Mel, there are many extra freebie scripts available that massively increase workflow. MJpolytools is a great toolset for quickly selecting edge rows and loops :http://www.maya3d.dk/Scripts/MJPolyTools/
Byrons poly tools are good too: http://www.byronimo.de/mainpage.htm
Connect poly shape toolset : http://www.lightstorm3d.com/download/html_en/cps.htm
There are many very useful mel scripts that pertain to subdivision modeling on this page here: http://www.chemicaldust.com/forum/viewtopic.php?t=9
Magnet soft select script for Maya : http://www.cgtalk.com/showthread.php?t=167488&highlight=soft+selection
Home of Maya : http://www.alias.com
Hair plug-in : http://www.joealter.com
Awesome freebie modeller : http://www.wings3d.com
Awesome almost freebie modeller : http://www.nevercenter.com
Community sites
Lots of cool stuff for free : http://www.highend3d.com
The biggest : http://www.cgtalk.com
Friends, colleagues and the favourite hang out of many talented professionals, students and hobbyists. I can be found here way too often: http://www.polycount.com
As SouL once put it "it's like Spiraloid on crack" : http://www.chemicaldust.com