Working with Talent Agencies for Castings
 

I have been posting up Casting call all across the internet and I have had some people e-mail their headshots and resumes. They have phone #s on there but they are for a Talent agency. I want to call them and set up an appt. for the actor to audition. So my question is, has anyone dealt with a casting agency? I mean I don't want to be calling blindly and make it sound like I don't know what Iam doing, if youu kow what I mean. They know that it is a non-paying job of course. So how should I go about trying to get this actor to audition for me? Sorry to be so convoluted.