I got the house batteries, well, one of them charging from the alternator today.
I used the cheap charging thread by eldave (I think that's it) that is very nicely written up in the 12volt power systems section of this forum.
I don't have any fuses in the circuit yet (I need to find some) and the coil of red 14ga wire you see on the starter battery will be run to a keyed power source when I get around to it. For now I hook it to the positive on the battery while driving to activate the solenoid and unhook it while parked.
I took a set of 20 foot 4ga jumper cables and cut off the clamps at each end and crimped on eye connectors using a punch and my vice. After the effort I went through sealing the holes in the floor from the seat rails, I drilled a new 1 1/4" hole through the floor under the battery compartment to get it inside. It follows the rear heater lines up into the DS side of the engine bay and runs across the top of the radiator over to the starter battery. I'm still figuring out how to seal (water proof) the hole.
From the house batteries I currently have my 3000 Watt inverter and a lighter outlet for my fridge.
I will also power some LED lighting and two more lighter outlets located at each rear corner of the van.
Additionally I will have 12 volt power coming in from a future solar panel installed on the roof. I'm currently agonizing over where to bring in the wires. Through the roof, or as I will be exploring, through the back of the van behind the curved plastic panel above the rear DS lights?
That will probably be it for wiring unless we decide to install a shore power 120 volt outlet. (uhg, more holes in the van)