Characterization is all important. Below are links to articles and websites which will help you build characters.
Tami Cowden's great book, Heroes and Heroines: Sixteen Master Archetypes, is amazing but she gives away some of her secrets on her website:
www.tamicowden.com/archetypes.htm
Caroline Myss has another great site for archetypes. It isn't a writer website - she teaches how to use archetypes in life - but it rocks as a source for character arcs.
http://www.myss.com/free-resources/sacred-contracts-and-your-archetypes/appendix-a-gallery-of-archtypes/
Alicia Rasley has two books on my 'favorite' list, The Power of Point of View and The Story Within series of workbooks. Here are a couple of her articles on character:
http://www.aliciarasley.com/artpovquestions.htm
http://www.aliciarasley.com/artexternal.htm
This particular site (fictionfactor) has a WHOLE bunch of great articles - I just gave you a few that I really like.
http://www.fictionfactor.com/articles/casting.html
http://www.fictionfactor.com/guests/unforgettable.html
http://www.fictionfactor.com/guests/flaws.html
http://www.fictionfactor.com/articles/platypus.html
http://www.fictionfactor.com/articles/mannerisms.html
Here's one for villains!
http://horror.fictionfactor.com/articles/villains.html
Remember I told you we'd interview our characters in this class? Here's some of the many lists of questions to ask.
http://www.tarakharper.com/k_char2.htm