The "b" is the flat which is the lower one, and the "#" is the sharp which is the higher one. For example: Eb is lower than E. G# is higher than G. The scale goes like this (from lowest to highest): C, C#, D, Eb, E, F, F#, G, G#, A, Bb, B. As you can see, the only two notes that don't have neither "b" nor "#" are the D and the A. The number next to the letter indicates the octave. I hope this helps.
