Tub Surround Transition Question

I am sheetrocking over my tubsurround, and as this is my first project like this I have no knowledge of how to finish the transition from the drywall to the tub surround. Is there a J hannel that is use there, or do I just run a bead of Caulk there and paint heavily? I looked at a friends bathroom and there didnt appear to be anything but sheetrock down to the tub surround. I am uing water resistant sheetrock and there is a lip that goexs behind it from the tub surround. Im just concerned about the edg of the sheetrock degrading over time.