The docs available here are invaluable for owners but also serve as a good introduction to the instrument for the curious.
There are a number of manuals for the Chroma, for the musician through the technician. The Programming Manual seems to be the most well-known and widely available, and is available here, along with the Parameter Chart. The Manuals page lists all manuals and provides links to soft copies and sources for ordering hard copies.
The Performance Manual, which is available here in hypertext, contains valuable information on basic patch editing, the cassette interface, audio hookups, and troubleshooting. The Programming Manual contains in-depth information on how to program the Chroma. The Service Manual is invaluable for those who want to do some repair work themslves—or have found a repair technician who isn't 100% Chroma literate. The Interface Manual contains technical information on the computer interface. Chroma Notes was Fender's short-lived Chroma newsletter. (Very short-lived: there was only a single issue.) Also there is the Fan Retrofit documentation which describes the optional fan and how to install it. And there is some warranty-related information for historical completeness: the Service Policy Guide and a scan of the warranty form.
Technical Service Bulletins
Along with the Service Manual, these bulletins provide essential service-related information for current owners. The Service Notes are brief bulletins about parts and, in a couple of cases, events (which at this date are only of historical interest). Eight Field Change Notices go into greater technical depth about modifications to the instrument, and include schematics.