Need to associate records from different forms in a Parent/Child relationship

I'll try to describe this as simply as possible. I would like to have a form where users submit information (Form A). Then I would like for other users to be able to review those entries and provide a rating. So Form B might be as simple as an record ID/Key from form A, a user ID and a rating (probably a scale field). How do I go about associating the two forms using this parent child relationship?  Eventually I would like to display an average user rating for the item in Form A if that affects anything. Having a hard time grasping this but it looks like others are doing something like it.