Topics

http://www.gdtopics.com/
http://groupdiscussionlist.in/

FAQ's / PPT

http://www.freshersworld.com/interview/gd_faq.htm
http://www.careervarsity.com/careertools/GroupDiscussion.ppt

Sample Mock GD

http://www.freshersworld.com/interview/gd_mock.htm
http://www.freshersworld.com/interview/gd_mock1.htm

Factors / Skills

http://www.humanities.manchester.ac.uk/studyskills/groups/discussion/
http://www.lc.unsw.edu.au/onlib/pdf/disc.pdf

Evaluation

http://www.evaluategroup.com
https://www.google.com/search?site=imghp&tbm=isch&source=hp&biw=1280&bih=600&q=group+discussion+evaluation
https://www.youtube.com/results?search_query=group+discussion+evaluation