How to start the GNU Fortran compiler.

I just installed the GNU Fortran compiler on my MAC OS X machine. I seemed to install without any errors, with the message "The programs have been installed in /usr/local/gfortran/". How do I start this compiler? I can't find any directory named /usr/local/gfortran/!

Is GNU Fortran the best choice? I have a small legacy Fortran program that I would like to convert (and extend) to python.

Thanks, Jerry