Ask each of your teachers which style they want you to use. If they have no preference, you can use any of the following:
APA: psychology, education, and other social sciences.
MLA: literature, arts, and humanities.
AMA: medicine, health, and biological sciences.
Turabian: designed for college students to use with all subjects.
Chicago: used with all subjects.
EndNote Web comes as part of the Thompson ISI Web of Knowledge database subscription.