Path of Exile free to play in about six hours.

[LennyLen]

I'd recommend fighting your way to the Ledge and running that a few times. It's really great XP, mob density, and easy to run.

I'll second this. I was in the same position going into cruel difficulty - all my gear was low level. I spent a few hours farming the Ledge and replaced nearly every thing I had plus gained four levels in the process.