Arachnid Labs has come out with circuit pattern trading cards. Most electrical circuits are composed from a relatively small number of common patterns that can be designed and analyzed as units. The engineer can then compose these individual sub-circuits into a completed device.
Arachnid Labs took this and produced a set of 32 trading cards that illustrate some of the most common ones. Once you recognize these patterns, you will begin to see them in every schematic you see.