As someone who hasn't really PvP seriously ever, at all, I now find myself having to do 2 battlegrounds for the legendary stuff.
As I don't want to just sit around and hope that the rest of the team is any good and would like to actually help them win, I'd kinda like to read a guide on what I should really be doing. What talents are best for PvP, what pet, what spec etc.
My usual hunter resources don't seem to have one - anyone know of any good up to date pvp guide?
Candidly? It doesn't matter. You're going to be fully dependent on the luck of the draw to do those. Just toss on whatever pvp gear you have for the resilience and power, and roll with it. Things to focus on: snares/stuns/cc you may not normally keep on your bars as well as Widow's Venom. With persistence, you'll get your wins. Bringing friends helps too.