A tip from Des led me to a promising site devoted to the Nahuatl language of the Aztecs. Unfortunately, it promises more than it delivers; only five of the projected 22 lessons are online, but those include an excellent one on Phonology, Orthography, Accent, and Syllable Structure. So if you’ve ever wondered how those exotic-looking words are pronounced (Xochitl, anyone?), here’s your chance to find out. (There is also this site, with the modest title “Inadequate Nahuatl Lessons”; it describes the classical language in a distinctly less rigorous way, but on the other hand it covers more ground, so makes a useful supplement. It’s accompanied by an “Inadequate Nahuatl Reference Grammar,” which presumably goes into more detail.) There’s a short glossary here, and a map showing where the language is now spoken here.