Below is a collection of resources on assemblies and how they're formed and structured:
In 1999 there was a large scale mobilization and convergence in Seattle in opposition to the World Trade Organization. A diversity of tactics including marches, non-violent direct actions, street theater, and black bloc were used to shut down the city. In the wake of Seattle the Direct Action Network (DAN) formed to create a directly democratic organizing body and coordinate similar actions in the future.
People's Global Action (PGA) was the European counterpart to DAN, and coordinated affinity group based actions against corporations throughout the contininent.
Occupy Wall Street sought to build on the examples of DAN and PGA in the context of the 2011 global uprising. Through assemblies and spokescouncils hundreds and at times thousands of people were able to coordinate daily functions of the occupation as well as targeted actions against banks and large scale convergences