I suggest you also read,and ask your questions in an RV (recreational vehicle)
newsgroup. They deal with most of the items you need help with.

sel1 wrote:

Can anyone direct me to some sites where I could get some ideas on what I
should be doing to wire up a boat correctly (with diagrams - I prefer to
see things) for properlly servicing the boat and managing the batteries
properly. Beyond lighting I'm not sure what I could/should be planning for.

From threads in these ng's I've come to the conclusion that most chargers do
not top off the batteries. Is that correct? There must be some commercial
off the shelf chargers that can do the topping off?

What kinds of useful 12v appliances are out there?

Thanks