205 logic gates and combinational circuitry

It's not very complete, but this site does have a nice illustration of a quad NAND gate and illustrates some pastimes with it.

A nice explanation of sum-of-products in a few drawings from Bob Brown, spsu.edu

Very simple digital logic from Princeton

Good pictures of combinatorial circuitry at a somewhat higher level that we're doing, from UConn

Here are some encoders and decoders at a good medium level of complexity