When you are writing music, when do we know when to write the stems facing downwards or upwards?

Question

I'm talking about the notes for music.... primarily piano... Is there a general rule of thumb I need to follow?... does anyone know any good sites? Thank-you very much in advance!

Answer 1

b and higher has the stems facing down

Answer 2

aww dang i was hoping someone before me would answer so i would know to lol but all i could think of is search on google.com or yahoo.com