AGH! What do these numbers mean?
 

I must be some kind of string instrument imbecile because I can't make this out. I am learning to play the bass and my book uses notes, then I go activebass.com to check out music there and I see number instead of notes. What do they mean?

fret number

Your book uses sheet music? I guess it tells you how to read music as well?
The numbers are fret numbers.
everytime you go up a fret you go up a semitone.
there are 12 semitones in an octave
the semitiones for each string are
E, F, F#/Gb, G, G#/Ab, A, A#/Bb, B, C, C#/Db, D, E
A, A#/Bb, B, C, C#/Db, D, E, F, F#/Gb, G, G#/Ab, A
D, E, F, F#/Gb, G, G#/Ab, A, A#/Bb, B, C, C#/Db, D
G, G#/Ab, A, A#/Bb, B, C, C#/Db, D, E, F, F#/Gb, G,

the first is 0 the last is 12.

I hope that wasn't jibberish.

Oh no, I already know how to read music, I was just confused about the numbers. I looked at the tablature guide on the web site and figured it out. Thanks all.