The maxim 'you get what you pay for' applies very much to art supplies, but beware of overpriced hobbyist's materials. Prettily boxed drawing sets can be attractive but may contain products you don't really need. Drawing is the simplest, cheapest medium, so invest in quality products. All you need to get started is a sketchbook or paper, a few pencils, an eraser and sharpener.
Pencil is the simplest, most essential drawing medium. Drawing pencils have cores made from powdered graphite (not lead) fired with clay, varying in hardness. Select a small range to begin with: an HB, a 3B, and 6B. will allow you to experiment with all the different weights of pencil, which is useful for realist drawing. Choose a reputable brand, as these will have better quality cores with minimal irregularities in tone, and will break less. Graphite is also available in bar, stick and powdered form.
Charcoal is a favorite medium for sketching and figure drawing. Charcoal comes in three main types. Willow, is light, hard and brittle. It is powdery and easily rubbed off, so mainly used for light construction drawing Vine charcoal, a fine quality natural charcoal, offers a full range of tone yet is easily erased. Compressed charcoal is available in varying hardness. Its dense tone can be difficult to erase and blend. It is available in stick form, particularly useful for large areas, and in pencils, ideal for fine detail. In addition, you can buy powdered charcoal that can be brushed or rubbed onto the paper.
Drawing Pens and Inks
Ink is a simple and elegant drawing medium that builds confidence. Inks vary widely in quality, opacity, and viscosity, and drying speed. Waterproof ink will enable the addition of colour without the black bleeding in, but clogs technical and fountain pens. Look for a good quality drawing ink bottled drawing ink appropriate to your preferred pen type. Note that 'black' can wash out to blue-black, brown or grey depending on the pigment or dye used. Experiment with fountain pens, old-fashioned dip nibs, sticks, and try cutting a quill. Also try drafting pens, or commercial lightfast felt pens.
Erasers are a useful tool, not just for mistakes! You will need at least two: a kneadable eraser for pencil, charcoal or pastel (pull and fold the eraser like putty to get a clean surface), and a white plastic eraser. It can be cut with a knife to make a fresh edge for erasing crisp lines. Many artists also like Art Gum erasers, which leave crumbly particles that absorb graphite and are gentle on the surface.
SharpenersThe standard two-hole razor-blade type does the job just fine, if it is new and sharp and the blades are straight. A poor sharpener will break the point. You may see rather a lot of your (expensive, pigment) core being wasted and prefer to use a blade to sharpen your pencil. Fine sandpaper is useful to improve the point; rubbing the side of the pencil on rough paper will bring back a slightly dulled point. This also works well for charcoal.
Paper Stumps / TortillonsTortillons, or paper stumps, are a useful blending tool. Made from fibrous paper rolled into a stump, they can be cut to a point or used for broader areas.