Jennings holds degrees from Harvard University, Columbia University's Teachers College, and the Stern School of Business at New York University. He became a teacher and was named one of fifty "Terrific Teachers Making a Difference" by the Edward Calesa Foundation; he also came out as gay to his students.[1] In 1990 he founded the Gay and Lesbian Independent School Teachers Education Network (later changed to the Gay, Lesbian and Straight Education Network), which seeks to end discrimination, harassment, and bullying based on sexual orientation and gender identity. In 1992 he was named co-chair of the Education Committee of the Governor's Commission on Gay and Lesbian Youth in Massachusetts. Jennings has authored seven books, including one which won the Lambda Literary Award.