Basic mechanical knowledge helps ie knowing roughly where things go.Dont be afraid to ask specific questions ,after you've done a search first . I acutually look at the modelling forums first, someone probably a few someones will have built it before you, one of them at least probably detailed it. Car mags, some better than others,check your local library for a manuel on the car in question. Two other considerations, not everything translates to scale eg some things will have to be made to big to look in scale and other bits wont be noticed and treat each part as a seperate model eg the engine bay as a whole model on its own same with interior etc