I started tanking Heroics right when I dinged 70, Mainly in Blues and greens... maybe a epic or two. The thing about heroics is the guys hit really hard. In the gear I had back then I was getting for around 7k by some bosses, and it was brutal with only ~11k hp. So the tank's and healer's gear should be pretty good. I would reccomned, if you're a healer, go pvp for some gear, the S1 stuff is a pretty good start and isn't to hard to get.  If you're a tank, its a different story, you could get s1 and gem/enchant it out with tanking stuff, but its not great. You would need to get craft as much as you can and put the best gems you can ( 12stam/8defense imo)
And if your dps, get ur pvp stuff too, it works alright in there.