A good resource for DC wiring is a small book ' 12 volt solar power's by Michel Daniel published by Permanent Publications in the UK. Don't be put off by the small size and dodgy line drawings, I used this as the basis for wiring our house 12volt circuit (we're off grid and have inverters and a back up generator for the large load 240v appliances - washing machine, toaster, blender etc). He has some good ideas in the book for running some common electrical items direct from 12v - I've used his suggestions for our TV, stereo, laptop etc.
