I have a big project (interactive theatre) where eventually I would like around 100 Arduinos networked. All nodes need to tx/rx with all other nodes, preferably in a multi-drop/daisy chain setup, but a star may be ok too.
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Whatever I end up with, I'm basically starting from scratch in terms of knowledge which is kind of terrifying/exciting.
That sounds cool!
If this is your first experience with programming/electronics I would probably say: 'prepare to get frustrated, angry and then maybe pleased'
That was a pretty big project if you're starting from scratch. 
There is nothing wrong with that!
I would suggest that you break your project into smaller problems, and be sure to make a sketch for each solution. And comment all logic that is not self explanatory.
(That way it's easy to browse old code, and see what worked and what failed. And if commentet well, why it should work)
100 networked arduinoes... Tell me more about your project? It sounds interesting;D