I bought volume 1 of Wonder Woman and loved it, and I want to support her series(because apparently any title, no matter how well written, is in danger of getting cancelled if it isn't Bat-or-Superman related), and I wanted to know if issue 20 is a good place to start? Is it the beginning of a new story arc, or should I buy a few back issues to catch up?

Yeah, issue 20 is not a bad place to get started, but there's always value in back tracking a little.

Enjoy

If you're able to I would recommend getting all of them since Wonder Woman kinda seems like its just been one big arc so far.

wonder woman volume 2 by perez,then ruka run.

Vol. 2 of Azzarello's run is great and has one of my favorite WW issues (#10) so I'd definitely advice to get that book.

I think the question is about the current run, right? It's possible to jump in now, but I would advise reading the earlier issues - this is a story that's been building since day one. Also, the run has been really good, so it's a quality read (and the first 12 issues are available in 2 TPBs).

I recommend reading all of the back issues - it is just a great series. The first several issues are hard to find though, so it's good that you've got the trade paperback. Volume 2 is out also, so that'd leave you not as many single issues to find.

This!

New 52 WW has pretty much been 1 giant arc. It might be more enjoyable to read everything so far. (If we're talking pre-52, I made a thread on here where I got great recommendations)