This is a very concise article about the stages of psychological development. It presents the primary development outcomes expected at each stage of life.
I found the study of developmental psychology extremely helpful for understanding the effects of PTSD. My personal theory was that the abuse and trauma I experienced in childhood had an impact on my development, something that is supported by scientific and medical literature. That abuse — and my response to it — had a direct effect on the development of my personality.
I have also found that the response of others in my direct social environment played a key role in shaping my development, not just the actions of my abusers.
Wikipedia has an excellent reference as well. http://en.wikipedia.org/wiki/Erikson%27s_stages_of_psychosocial_development