Yes, there's a new nav bar item to the left for the DVD Review area. You can access the user reviews from that nav bar, or from the DVD Release information page. To write a review you can either do it from the DVD Release info page (if there isn't a review for that release yet), or you select it from the bottom of the Reviews page for that release. I'll move that little link to a more noticable location later. Maybe there will be a little icon or something like that.
Anyway, have fun with the new toy. You can write garbage stuff for now and I'll just delete it later. Any "real" reviews will be left on the site.