Here’s Amy Cadle from Unidos de San Diego with a video showing the basic pattern each instrument plays in the bateria and how the parts relate to one another. She also demonstrates how the ensemble starts, stops, and plays breaks (bossas):
Here’s a similar video by Carl Dixon of Boulder Samba School, in which he demonstrates the basic groove of the bateria and common elements such as the chamada and viradas:
And here’s Vila Isabel playing on the streets of Rio, showing how it’s done in Brazil: