On the information screen (select the tab with the blue I) you see small white square with a green $ in nations with new trade consulates.
To learn about the commodities these nations produce select the small ship at the bottom center of the screen, and then click on one of the nations showing your trade consulate icon. You see a list of major exports.
As you become more friendly with this nation you will gradually be able to rely on deliveries of some or all of these commodities. You can increase the likelihood of trades by granting these nations trade subsidies.
