I teach many beginner drawing and painting classes and I have learnt that for those starting out in art one area that can be very daunting is materials. What should I buy? What are the differences between the pencils? These are frequent questions from beginners, some of whom have not drawn with a pencil since schooldays.
There is no right or wrong answer to this question, using pencils is just like using pens for handwriting, it is the one that feels right for you. However there are some general points to consider.
The grades of pencil range from H (hard) to B grades (softer) the higher the number the softer the pencil so for example a 6B is a very soft pencil and softer than a 2B pencil.
I advise my learners to get a set of about five pencils of different grades, that way you have more scope for creating a range of tonal values. What is a tonal value? This basically means how light or dark a tone is. The softer pencils create darker tones and the harder pencils (those in the H range) will create light, faint lines. For sketching and drawing we tend to use the B range of pencils.
See my Art Materials page for more advice on materials