The Interactive Typography Cheatsheet has a nice balance of usefulness, without the fluff and over complexity that seems to be the norm.
You simply hover over any of the green areas, and the respective type description will pop-up.
There are plenty of Typography Cheatsheets out there on Google, some good and some pretty terrible.
If you’re new to typography, and not sure what a spur is, or a counter, or maybe a bowl, then this will be quite fun to poke around,
Typography Series: Type Anatomy, Ligatures, Numeral Sets
As per his Deviant Art page, Martin has created two other useful typography related poster series for Ligatures and Numeral Sets:
Typography Series – 01 – Type Anatomy
The ultimate guide to the anatomy of type. I believe all the basic anatomy of typography is included. I hope you like it, and feel free to share.
You can now download a zip file including the file as a 2000px wide jpg and an .ai vector file so you can print the poster as big as you want.