one of these days I’m going to write a detailed userguide about how to get around on these babies
but until then, here’s a pic of the destinations/fares board..
and a link that tells you 80% of what I was going to write anyway:
http://thaitransit.blogspot.com/2008/03/mass-transport-boats-of-bangkok-klong.html (unfortunately now dead)
and the very good official one :