SOD's tutorials
The tutorials take you through each of the major aspects of a SOD run to explain what data SOD gets for a given recipe. After reading them, you'll have some idea of SOD's capabilities and how to write recipes to take advantage of them. You should probably read them in the order listed here.
Network Tutorial
The network tutorial explains how SOD gets stations and channels.
Event Tutorial
The event tutorial walks through SOD's earthquake retrieval system.
Waveform Tutorial
The waveform tutorial shows the way SOD takes the earthquakes and channels to get seismograms.