Thanks for all the help so far everyone. I'll try to give updates and answer all questions in this reply.
Regarding the solar panel having a controller, I suppose it may not. The only thing I read on the matter was the following line:
"All DuraVolt Solar Panels are self-regulating and typically require no additional controller or voltage regulator."
Document source here:
I guess I just read that and assumed there was a controller, but re-reading it, that certainly may not be the case.
Regarding my power requirements, they are quite minimal. The boat is a Catalina 22. The only powered accessories that I have used with ANY regularity at this point (and even then not often) are the running lights and 1 or 2 small LED cabin lights if I get back to the dock late. I do not have a radio, electric bilge, depth finder, GPS, etc. No need for engine cranking - I have a tiny, hand-start 4 hp motor. As stated previously, I just do daysailing on my local lake. This isn't liveaboard, blue water sailing. Truthfully, up until this point, I could probably do everything I need without even having a battery. If needed I could use a little LED lantern in the cabin and just have my wife sit at the bow holding a pair of flashlights for running lights until we make it to the dock.
BUT... My goal is to start using the boat more often as an overnight camping experience. Probably going out no more than once per month during the summer and staying only one night on the water. Even in this situation, all that would really be required are the LED cabin lights, LED anchor light, and probably cell phone charging. I don't know what the power requirements for that would be, and I can certainly sit down and come up with the numbers, but I wouldn't imagine it would be much.
I agree that until you know your power requirements, it's impossible to say how many batteries you would need (and therefore the charging requirements), but I guess I just figured that my requirements were so minimal that even a single battery and small chargers would be more than sufficient.
However, even without hard numbers, based on my proposed usage, and recommendations on a bigger solar panel and/or shore charger (if needed)?