As a TA, you should expect to do the following:
Design and prepare lessons and activities
Lead class discussions, activities, etc.
Give students feedback on their work- both written and verbal feedback
Meet with your leadership teacher on a regular basis
Attend biweekly after-dinner meetings with all TAs
Serve as a role model and a mentor to the younger students, both in and out of class
Attend every class meeting (most TAs have 2 class meetings per week, but some will have 4)
undergo and model an honest self-evaluative process: seek out feedback, utilize constructive criticism
teach the class if your teacher cannot be there for some reason