Try "Lighting for Film and Electronic Cinematography" by John David Viera, Dave Viera, "Set Lighting Technician's Handbook : Film Lighting Equipment, Practice, and Electrical Distribution" by Harry Box, there’s another I’ve seen. It’s a little green book that DPs use as reference for focal lengths, F-stops and such, but I can’t remember what it is. Anyway, if you want to be a DP, then learn all you can about lighting. That’s 75% of it.
If you can afford it, get a dual incidence/spot light meter. They’re not cheap, but the will give you readings that are exponentially more accurate than the camera. If you can’t afford a dual, get a incidence. If you have to use the camera, use the zebra lines. It should be lit so zebras just start to show on the brightest areas of the frame.