Thanks everyone for your helpful advice. The guy who's going to do this for me is going to put fabric underneath the pavers and, I believe, add some rocks and sand. I'm really not concerned about whether the area is level because I won't be walking on this except to place little decorative figurines, or whatever. If, over time, some pavers are higher than others, that's OK. I just hope that I don't have to fool with any more weeds. We have a commercial around here that states: if you give a weed an inch, it will take a yard. Nothing truer was ever said! My yard looks like a jungle. It's going to take a lot of money to have all of it cleared out and steps taken to try and ensure they won't come back--at least not for a very long time. This year has been the worst ever!