I love giving help and advice!
Here's how I understand the Team resource:
The game starts with 1 Team in the pool. Whenever we skip a significant amount of time, the pool resets to 1 Team. Several actions have results where we can gain more Team. The primary way of gaining team, though, is the enter battle against a dangerous foe as a team move. This is the one we did when we picked a leader. We got a big pool of Team added for that.
Whenever a roll is made, any other player can spend 1 point of Team to add +1 to the roll, after seeing the result. You can only do this if you can explain how your character is helping. This can be done multiple times per roll, but only once per hero. For instance, Polaris rolls a 5 while trying to bind the villain. If Omen spends 1 point of Team and describes how she grapples the baddie, it bumps it to a 6. That's still a Miss, so then Mimic runs up to help, spending 1 point of Team and describing how he formed manacles on the villain's wrists. That would bump it to 7 and Polaris would get a Partial Hit instead of a Miss (she also wouldn't get the point of Potential for the Miss).
You can also use Team selfishly. To do this, after your own roll result, you spend a point of Team to give your own roll a +1. You then have to describe how you've been selfish in this action, or have done something rude/wrong toward your teammates. The example that the book gives is that the Delinquint is trying to distract a bad guy from hitting him, and he uses illusions of his teammates to do so.