1. One thing that might be useful to persons in their first encounter with the concept of Project PM is a page with the logo, and under the logo a paragraph explicating the symbolism of the logo, the paragraph being in effect a statement of the network's structure and purpose.
2. Along the same line of thinking, concentric rings of overlapping circles may be a better representation of the network's structure than a diagram with lines for relationships or arrows for routing of pushed posts, because the latter will be too complicated visually, even if you introduce color for differentiation.
(Google docs does not have a template for overlapping circles; I will see if I can find one online.)
3. A diagram with arrows might be useful to show a very local section of the network, such as how it works for one member blogger.