Have a look at my gear guide - it should help you if you're looking to gear up for instances:

Stealthy's Elemental Shaman Gear Guide for Northrend (Horde)

As others have said, you really need a dedicated tank for instancing, or you need to get 2-3 levels higher before hitting the lvl 70 instances.

Once you hit 73, starting doing the dailies in Grizzly Hills - they will give you a nice chunk of exp and can be completed pretty quickly.

Cheers,

s.