When doing art with traditional media, a popular choice is Pencil. There is a wide range of pencils, in many different types. A very popular art pencil is the Graphite Pencil.
Graphite Pencils are usually made of graphite sticks, encased in wood, but there are some graphite sticks without coating. They come in a range of hardness from 9B, the softest, to 9H, the hardest. "B" being more brittle/soft and black. "H" being more hard and light. HB being in the middle.