If you click the image it will make it larger and easier to read. I tried to wire this up on the bench to replicate what one might see on-board a boat. This is explanation is just far to difficult to illustrate on a boat. I actually photographed this quite a while ago, on a boat, and decided not to use any of the photos.
Obviously the house bank would be multiple batteries but the point is the same and a single battery was used for illustrative purposes only. If your boat is not wired with a positive or negative distribution buss it can help organize the wiring tremendously.
I have also shown a Blue Seas double MRBF (marine rated battery fuse) block on the battery post. I use one for the house bank and one fuse for the alternator which I generally always wire direct to the house bank.