Graphite pencils range from ‘H’ (hard) for light shades to ‘B’ (black) for dark tones, with ‘9B’ being the darkest and softest. Different pencils are best for varying uses: softer ‘B’s for intense shading, harder ‘H’s for fine lines, and mid-range like ‘HB’ for versatility. A combination of mid-tone and dark pencils can create a full spectrum of shades for realistic sketching.