When sighting and measuring for a painting or drawing, there are two essential tools to have on hand: a straight skewer and a plumb line. Skewers are easy to come by, as one need only utilize a thin metal knitting needle or straight bamboo stick; plumb lines can be constructed with two simple elements: a thin length (a little less than 1') of dark thread and a weight.
Paper is the support on which a charcoal drawing is made. There are numerous brands of charcoal paper available, but many are too delicate (and too expensive!) to be very helpful to the beginning student. Each type of paper has its own personality, with pros and cons.