Let's take a look at all the notes on the high E string, up to the 12th fret where the notes start to repeat. Try the quiz to make sure you've locked in the knowledge.
E String Notes
Some accidentals are notated with a "b" (flat) and some with a "#" (sharp) based on the likely occurrence, due to the commonality of some key signatures over others. For example, Bb is a more commonly seen note than A#, although they are the same pitch.