How/where do we set commission for Affiliates?

This seems so complicated! Seems like Affiliates does not work stand-alone, and we must use membership, marketpress, or pro sites in order to use it? In the short run, I don't want to use any of those. Will simply using with a paypal button on a purchase not work? I want to pay $10 per member affiliates bring, no matter how much the membership is. Is this possible? Is there an Affiliates manual, or video? Feels like a big chunk of info is missing.