Start with a steel frame contoured to the correct bends, add a strip of steel to the top and sand it to get all of your spacing correct around the perimeter. When all this is done (including the hinges and reinforcements for the hood latches), you get a sheet of aluminum and start working it with an english wheel until it lays flat on the hood frame you already made. At this point, rivet the panel to the frame at the front and slowly begin working the edge of the aluminum over the steel strip (a torch is useful to put some heat into the aluminum). When the edge is completely done, mark your hood opening and cut it.
Then, back to the wheel to build a hood scoop of the size you wish. Of course, you can skip this if you want the street car look (which IMHO is cleaner). If you want professional type videos and resources, I do not think you can beat Kent White. I took his classes years ago, and he is one heck of a craftsman.
www.tinmantech.com