Choosing Sketching Pencils:
When drawing in lead pencil most artists tend to favor a small number of shades available. If you want to begin sketching you may like to start of with 4 pencils; 3B, B, HB & H which will give you good variable of shade without purchasing a full set of sketching pencils. Looking at the illustration above 6B is the softest/darkest lead, HB is in the middle and 4H is the hardest/lightest lead.
Artist quality pencils can be purchased from any Art Supply Store or for specific pencil brand information see: Artists Pencils
Another artists drawing tool, simialr to a pencil is a Silverpoint used for Silverpoint Drawings.