Question: What do the H and B and numbers mean on a pencil?
Answer: Simply, the H means hard and B means black. H pencils, because they are hard, leave less graphite on the paper, so are lighter. B pencils are softer, so leave more graphite on the paper, and so are darker. F means Fine Point, and it is quite a hard pencil - easy to keep sharp, but generally a bit too hard for general drawing. The more Hs, the harder it is (so a 4 H is harder than a 2H) - HB is kind of in the middle, though for drawing, its still reasonably hard - and the more Bs it has, the softer it is - so the 7B is the softest.
HB is equivalent to the standard American Number 2 pencil, B is Number 1.