There is a PDF tutorial.
A Quick Guide to Coot's Keys and Buttons, print it out and stick it on your wall.
Documentation on the scripting interface. This displays the fuction names from the point of view of a python scripter (scheme scripters will have to do a trivial name mapping (described therein)).
Documentation for the Coot functions written in scheme.
Documentation for the Coot functions written in python.
And for the hard-core Coot scripters, there's The Coot Reference Manual (note: this is autogenerated and doesn't make for light reading).