There were some good questions about hiring workers guild chat last night. Some of the basic essentials of workers are not at all obvious in this game.
Here's a quick list of things that every player needs to know.
1.) Hire workers and put them to work immediately. It is as necessary as leveling. Get started as soon as you have two or more contribution points.
2.) Workers do not use your energy points to gather. Much more efficient than do-it-yourself.
3.) Workers level up and get bonuses and promotions as they work. This is another important reason to not wait until endgame to hire a full task force. Hire them and deploy them early and frequently, and keep leveling them all.
4.) A worker lives in the town in which he is hired. You can send him on a long commute to work elsewhere, but he'll spend more time commuting back and forth, then, and will always put his harvests in his hometown warehouse. You cannot relocate him. This can work to your advantage, though, if you prefer to have products far away delivered to your base of operations.
5.) To deploy a worker, you need to put a contribution point into the node, and then you need to put another point into a field or mine inside that node. If you put one point into Casta Farm, you cannot deploy a worker there. However, if you put one point into Casta Farm and then one more point into the grape orchard inside Casta Farm, then you can deploy a worker there.
6.) If you havent made up your mind about where to start, get the Bartelli Farm potato field south of Velia, and put a worker from Velia or Olvia in it to harvest potatos at all times. No matter what your strategy is, you will always need potatos. Bartelli is a good choice because it will also serve as a critical node link that you will keep forever.