1duxfan said:

is there a way to protect troops while harvesting lumber, silver, iron, etc...? Or troops while marching? i have a safe harbor resource, but not sure how to use it? and when? and from where?

Safe conduct.

Once you've captured the tile, click it. It will note the tile is unprotected, and if you have no Safe Conducts. If you have Safe Conduct(s), a red button will be present you can click to shield the tile. A new window will appear confirming application.

If you have more than 1 Safe Conduct, the window will also let you apply more safe conducts. i.e. You are not limited to 1 or 3h of safety, you can add a 2nd hour to make 2h, etc.