Hey Mike, welcome to the forums! You will get a ton of useful information here.
Another thing that most of us do (well I do anyway) is leave the gray tank valve closed for a few days before I dump the black tank. Once you pull the handle on the Black tank and it all runs out, you can close it and open the gray tank valve. This will rinse out the sewer hose for you. Its much better to deal with a little soapy water from the gray tank than dealing with what comes out of the black :)
So the procedure is this, once you are connected with a hose from the camper to the sewer, pull the black tank valve and let it drain. Leave the valve open and connect your water hose to the inlet marked tank flush. Turn on the water and let it flush the tank out for a few minutes. Turn the water off, let it finish draining out of the black tank then close the black tank valve. Then open the gray tank valve and let the soapy water flush the hose clean. Close the gray tank valve, and starting at the camper, pick up the hose and "walk" it all the way to the sewer connection. This will make the water in the hose go into the tank. Double check that both tank valves are closed, then disconnect from the RV then the sewer connection. Put the hose away, and wash your hands.
Good luck!
SK
