Per Diem Travel Companies/Agencies

Hi everyone,
I have been emailing a bunch of travel agencies for a position here in Cleveland, OH in Labor and Delivery just some questions about rate of pay, insurance, just basic stuff. My question is:

Does anyone have a list of agencies that I can email or call instead of hunting and searching google, yahoo etc?

and 2

Does anyone have a list of good questions to weed out the bad agencies?

Thanks guys, i'm gonna post this in the agency forum too.

~Janine