So after 20 years of goofing around and playing in bands I'm finding out it may be time to learn the note's. It may sound dumb but outside of EADG I dont know any other note on the neck. I haven't had a problem when I sit in with others but I do get concerned looks when they call out keys and notes and I just nod my head. Any advice of things that have work for other players in a similar situation (ie: old dog new tricks)?
Since everyone else is arguing over an EXISTANT E#

I figured Id get you going.
Now remember that there is a sharp between every note when going higher in range up the neck (towards the bridge), every note except B (to c) and E (to f), this doesn't mean a B# or an E# don't exist, they do, and you may see them while reading music (if you do).
Anyway, if you know your standard E A D G, a five string bass adds a low string making it B E A D G and a 6 string bass adds a high string making it B E A D G C, there are basses that have more strings such as 7+ but chances are you won't encounter them on the norm.
So now taking what I said earlier you just go up the neck adding a sharp or changing to the next note in terms of transitioning from B to C and E to F, so:
A A# B C C# D D# E F F# G G# and repeat.
flats work a little differently, a flat "brings you back" so instead of climbing towards the bridge of the bass, you'll drop to the head of your bass (lemme guess, you play a headless?

) Anyway, what that means is a G# is the same note as an Ab (b is the sign for a flat and # is the sign for a sharp, sorry I don't know how much you know) a fancier term would be G# is the enharmonic equivalent to an Ab, and all that means is they are the same note so the sixth fret on your D string can be referred to as either a G# or an Ab, since the fifth fret is a G and the seventh is an A.
Here's a chart on the notes for a four string bass.
String fret note
E 1 F
2 F#
3 G
4 G#
5 A
6 A#
7 B
8 C
9 C#
10 D
11 D#
12 E
A 1 A#
2 B
3 C
4 C#
5 D
6 D#
7 E
8 F
9 F#
10 G
11 G#
12 A
D 1 D#
2 E
3 F
4 F#
5 G
6 G#
7 A
8 A#
9 B
10 C
11 C#
12 D
G 1 G#
2 A
3 A#
4 B
5 C
6 C#
7 D
8 D#
9 E
10 F
11 F#
12 G
You may have noticed that it stops at the twelfth fret, that is because at the 12th fret, it repeats, yes, they are the same notes, an octave higher, so playing 12th fret is equivalent to playing the string open, 13th is equivalent to fret 1, 14th is equivalent to fret 2 etc.
Another thing to take note of, the fifth fret on a string is the same note as the open name of the string below it (useful for tuning) so the fifth fret on the E string is an A.
And the seventh fret of a string is the same note as the open string above it, so the seventh fret on the A string is the same as an E above it.
Hope I helped, you can send me a private message for more information or questions.
-Mike