I’ve spent 2 years as a TA in graduate school–and the answer to all your uestions is pretty much yes. You don’t have to e-mail the professor AND the TA unless you want to. Usually, the TA will have office hours so you can visit and ask questions or get individualized help.

Don’t be concerned about the TA’s qualifications–by the time someone is qualifed for that, they have already more than covered any material you will have to learn in your class. In the event they aren’t sure about something, a good TA will refer you to the professor.

The only thing you need to keep in mind is that the TA’s responsibilities are set by the professor–and some of the items you mentioned might not be included.

A teacher’s assistant, otherwist known as a TA, is usually an upperclassman or even graduate student. In some cases, TAs can hold doctorates or beyond. TAs are there to help you because professors cannot possibly help everyone in the class that needs help. Sometimes even, TAs hold discussion sections in which they go over problem sets and clarify difficult concepts.

When you email, it is a good idea to send an email to both the TA and the professor so the TA gets a feel for answering questions and helping out. You can ask him any questions and he will help you out. He won’t give you answers on homework, but he will help you figure them out.