I've always been a fan of graphic presentations. More people understand graphs and diagrams than understand equations. While this is a bad thing in some ways, it remains a fact. So it's always great to see a graphical representation of a really difficult set of concepts.
Jeff Moser Fisher has posted A Stick Figure Guide to the Advanced Encryption Standard
(AES). He has wisely structured it in layers. Interested readers can learn about AES to their level of interest or understanding: they can get the history and process, the high-level summary, or go diving into S-boxes.