i went to UNAM's architecture dept. and bought a contemporary guide to architecture in mexico d.f. called arquitectura contemporanea. its a great book, written in spanish, complete with maps (which you will undoubtedly need). the university is a must-see, plus i had a good chat with some students hanging around in the bookstore. WARNING: be careful exploring for barragan's buildings as some are in very bad areas. mexico city is fucking mindblowing, do not miss the siqueros and orozco murals, casa azul and trotsky's casa, complete with bulletholes and the desk upon which he was bludgeoned to death. also drink pulque (sp?), if you can.

When I was in the DF I checked out as many Barragan houses as they would let me. There's a little orange book that serves as a useful guide and I've also written up some of my notes which may be us use to you. In addition to the Barragan stuff and what has been mentioned already, you may also want to Candela's Los Manantiales in Xochimilco and Juan O'Gorman's copy of the Ozenfant house for Diego Rivera & Frida Kahlo. If you do make it to the univ., Mathais Goeritz's Espacio Escultorico is cool too.

lucky bastard! i love mexico city. last time i was there was over a year ago and i've been dying to go back. i agree with the posts above. you should definitely check out el zocalo which is mexico city's central plaza. while there go to the palacio nacional which has huge murals by diego rivera on the complete history of mexico. also in el zocalo, the templo mayor, which was the main aztec temple of tenochtitlan, and the national cathedral which was built from stones from the ruins of the temples of tenochtitlan. also, the polyforum has great siquieros murals. this book may help.