Chill960: Thanks. I think I am getting it. I believe I have the valve in the outside compartment. I'll go to storage, check and make sure, and I have a feeling once I am standing there looking at it the whole thing will make a lot more sense.
Well, at least I thought I got it until I did a quick search for winterizing and came across this thread:
Fresh Water Tank Sanitization
So now my question is this (keeping in mind I have never winterized so I don't know how that process works): Assuming I have the little white valve you talk about that I can see in your picture with your water jug, and I have the hose with the threaded plug that Iggy mentions in the above thread, would I still need to do the adapter to the shower head to FW tank on the other end, or would I be able to just put the hose with the threaded end that Iggy mentions in the water jug and turn the pump on? [See VinceU's post toward the bottom of the first page on the above thread that essentially says the same thing as you.]
I am assuming the answer is no, and I am missing a critical step but I have no idea what I am missing.