I'm debating whether or not I should be a TA next year (my fourth year) or to wait until I'm in graduate school. I'm pretty undecided on it because I know I'm going to have quite a few courses in my fourth-year but at the same time I think it would be a good thing to put for applying to a graduate school. Ideally, I'd want to TA either biology or psychology, preferably first or second year. Biology has the option of teaching and marking or only marking but I'm pretty sure I'd go just for marking because I've been told graduate school isn't exactly a cake-walk. If it matters, I'd want to go for a PhD or PsyD in the end.

I'd jump at the chance of becoming a TA, although at my uni they don't allow anyone doing an undergrad or masters course to do it (i.e. - only PhD students can do it).

Anyway, what I'd do in your situation is find out when my dissertation/research project (whatever you may call it) is due to be all written up and handed in. In my experience (I'm a masters student at the moment), I found the time when I was doing my research project painfully time-consuming, since I had it and classes to juggle. My research took up the entire first semester and was to be written up for the end of January, and after then I had A LOT more free time. I dunno if you can start the TA position any time you want, but if so, I'd definitely avoid doing it at the busy time of the year.

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