The MPICH implementation comes with several kinds of documentation. Installers are encouraged to provide site-specific information, such as the location of the installation (particularly if it is not in /usr/local/mpi).
A complete set of Unix man pages for the MPICH implementation are in mpich/man. man/man3 contains the MPI routines; man/man4 contains the MPE routines and mpirun, and man/man5 contains the MPID routines (these are for the low-level part of the MPICH implementation, are are not of interest to users). The command mpich/bin/mpiman is a script that runs xman on these man pages.
Web (HTML) versions are available at http://www.mpich.org/static/docs/latest. A sample Web page is shown below, and is also available in mpich/util/mpichsite.html
Users often prefer working from example Makefiles and programs. The directory that is installed in the examples directory contains a C and Fortran version of the `pi' program, along with a Makefile.in. Users may be interested in some of the examples that are in the source tree, also in the examples directory.