Charts charts and more charts is a great thing but I just don't get what fret to play on what string?/?
When you look at a chart, see what key it is charted in. For example, if a chart is written for a song in the key of "Db", then wherever you see a "1" in the chart, you can play a "Db". For a 4 string bass, your lowest "Db" is the 4th fret on your A string. For a 5 string bass, your lowest Db is the 2nd fret on your B string.
Now, everything else is relative to where you started, based USUALLY (but not always) on your MAJOR SCALE.
So, if you know where your Db is, and you know how to play a major scale, starting with Db, then you can follow the chart by playing the chord positions. If the chart is written to play " 1----1-----4---5--1", I know that the notes are "Db----Db-----Gb---Ab--Db"
Now, the beauty of charts is that if my MOM says "We ain't doin' it in Db. I don't like Db. We're doin' it in Ab", I already know how to play it, because I just move the figure from a Db root note to an Ab root note, but the relative position of the notes is the same. Now " 1----1-----4---5--1" becomes "Ab----Ab-----Db---Eb--Ab". As long as I know where to find those notes on the fingerboard I can play the song.
If you are looking for exactly which fret to play on a particular song, tab helps with that. IMHO tab is much more limiting than charts. Charts at least provide incentive for learning your scales.
Peace,
James