The edges of the top and backing do not need to be "finished". That is what the binding is for. Check the tutorials on this Board to find one about creating the binding, and send that along to the quilter. The quilter will sew it to the front of the quilt when she is finished quilting it. It is generally the owner's responsibility to "slip-stitch" the binder to the back.
Both the backing and the batting are at least 2" larger than the top, to allow for easing in. However, if you have any questions about that, line up a quilter first, and then ask her/him what she/he prefers as far as how much hang over they prefer for the backing and batting.
If you have more questions, please feel free to ask. We're here to help! And please do post a photo when you're done! We'd love to see this quilt finished!