I typically leave the valves in "normal" operation setting once I've winterized--it makes dewinterizing it that much easier in the spring as I don't have to mess with the valves.
Dewinterizing is a pretty easy procedure: just pump water through everything watching to make sure no pink comes out. I usually do the following:
- Hook up city water
- Leave the plug off the water heater and run a little water until no pink comes out the plug
- Put plug in water heater (skip above and this one if the plug is already in)
- Use outside shower: Run cold until no pink, run hot until no pink (you'll have to wait until the water heater fills so this will take a while)--I use the outside shower because I can let that run as long as I want without filling my waste tanks
- Turn off outside shower
- Run through each faucet running both hot/cold until no pink
- Also run toilet
- Disconnect city water
- Put some water in the tank
- Run faucet closest to the tank to flush that
Obviously the above doesn't include sanitizing the system. That may look like a lot of steps but it isn't that difficult, just want to get everything covered.