The University of Rochester's Department of Physics and Astronomy has a posting about their TA training program. Here are some selected highlights:
provides information on teaching skills for graduate students, including references to workshops, educational resources and seminars.
Online resources
TA Electronic Discussion List is an electronic discussion list for college and university TA's all over the world. Discuss issues of interest and concerns to graduate teaching assistants. To join the list, send a message to listserv@unmvma.unm.edu. In the body of the message put: sub t-assist your first name your last name. Be sure the return address is the email address to which you want your messages sent.
provides:
Basic teaching tips to inexperienced teachers; ideas that can be immediately implemented into the classroom.
New ideas in teaching methodologies for all teachers.
A forum for experienced teachers to share their expertise and tips with colleagues around the world.
is a good place to look for a text or reference. Literally hundreds of books are online through this Carnegie Mellon service.
is another resource for free online reference texts.