T. A. teaching position
Pros: free courses toward ma.
Cons: low pay. no method or structured instruction on how to properly teach or design related materials.
My personal belief is that T.A. positions are extremely underpaid, as Universities heavily rely on T.A.s to teach the majority of undergraduate courses without paying them properly. Our department was limited to 2 Phds and 1 lecturer (who happened to be a Phd), all other courses were taught by 6 T.A.s at approximately $ 1,300 a month, which is not nearly enough for an average adult student to survive on, especially not if they have family. The Universities justify this low pay by the fact that you get to study the program for free, and they require you to only be a T.A. while you teach. They have lost touch with all of reality and in practice are just interested in providing cheap labor for understaffed departments. they get 6 T.As and are paying maybe for the equivalent of one Phd (or 1.5).
As a T.A. there are some things that are valuable, but you are basically doing everything for the school with no proper training to be a teacher, it is all add hoc. Even lesson planning (which is crucial to learning) is not taught in a course; it is mentioned and covered during orientation for an hour if you are lucky. You get to design all lesson plans, assignments, exam, etc. despite the fact that you really aren't trained or qualified to do so.
If you live with roommates, have no financial obligations to speak of and just want to get your masters without paying for it, than a T.A ship might be great for you. If you need it as a job DON"T go that route. You will be swamped by work, grading, designing, studying, testing all kinds of other related stuff, without true instruction and very little time left to do anything else.