What is gender?
Gender is commonly defined in terms of biology and anatomy. Although this may be more accurately called one's sex - male, female, intersex. One's gender also connotes the societal expectations associated with each sex - male, female, transgender.
What about gender identity?
"Gender identity is how we feel about and express our gender and gender roles — clothing, behavior, and personal appearance. It is a feeling that we have as early as age two or three."
[Planned Parenthood. Health Info and Serivces. Gender and Gender Identity (What is Gender? What is Gender Identity?) http://www.plannedparenthood.org/health-topics/sexual-orientation-gender/gender-gender-identity-26530.htm]
Don't forget the databases on the Welcome page. Here are a few specific to Gender.
A repository of important historical perspectives on the evolution of the women's movement, men's studies, the transgender community and the changes in gender roles over the years, covered in scholarly journals, magazines, newspapers, newsletters, and government and special reports. Coverage dates back to 1970.
Peer-reviewed journal articles and book chapters in the physical sciences and engineering, life sciences, health sciences, and social sciences and humanities disciplines.