Skinning walls and lots of Questions.

Well I am to the stage where it is time to stand the walls..... I already have them cut and the bulkheads and cabnints laid out. My question is should I stand the walls and build them from the inside or should I build and insulate the walls while there on the ground. I have been seeing it done on here the both ways so I'm not sure which way is better. Also if I build them while there standing how would I get the pattern for the shape of the interior skin??? My plan is on the lower bulkhead use 3/4 plywood and mount an air conditoner in the center. I will also put my elec. in there. As far as that how is everyone doing that part? Do you use all 12volt lights and use the 110 to run an inverter\charger? Sorry it is so long just to an exciting part of my build and don't wanna screw up. thankx a lot. Bill
