You can only build Boathouses on Rivers, you need to connect improvements up to either the town or boat houses to collect gold.
Edit: You can't currently get able men, and the turn counter is how far away you are from a town or boathouse, the caravans use this to determine the best route.
Edit part deux: Sorry, I guess I should explain that the gold is bugged and sometimes you don't get gold at the beginning, I ran out of time getting the economy up and running. Sorry that it isn't as 'game-y' as it should've been.
