Finding Rent Rate: Additional Tools BESIDES the MLS?

[Bill Mitchell]

What are some additional tools I can use to find rent rate besides the MLS? I ask because I am looking at a property in a very rental heavy area. I know the houses are renting here, the problem is none of them are being advertised through the MLS. The rent rates are a bit lower, perhaps that is why ($550-$800).

I know some people use craigs list to help supplement what the rental rate is. How does one go about doing that?

Thanks everyone