MadGraph documentation
generate custom processes: http://cp3wks05.fynu.ucl.ac.be/Manual/usrmod.html
particle naming: http://madgraph.hep.uiuc.edu/sm_particles.html
process cards: http://madgraph.hep.uiuc.edu/EXAMPLES/proc_card_examples.html
further examples of syntax: http://madgraph.hep.uiuc.edu/EXAMPLES/example.html
Fixing problems
If you have a process in svn and want to do ./bin/newprocess - adjust this script in line 127:
rm -r `find . -mindepth 1 -maxdepth 1 -type d -name "P*_*_*"` >& /dev/null
change to
rm -rf `find . -mindepth 1 -maxdepth 1 -type d -name "P*_*_*"` >& /dev/null
Otherwise you'll wait forever...