From Neural Wiki
To get a detailed background in FORTRAN, the wikipedia page page on the subject is a great place to start. I haven't bothered to go into too much depth since so many others have, I am only looking to make a reference for people like me who started off without knowing anything about operating in FORTRAN
 Getting Started
The old version of FORTRAN (G77) and the newest version (Gfortran) are very similar. The newer version simplifies a few operations, but does not necessarily run obscure code that G77 accepted. Gfortran runs faster than the old compiler, so if you are doing basic programming from scratch (not using old code) then Gfortran is probably the right choice for you.
Here is an interesting discussion on G77 versus Gfortran
To run FORTRAN, you must install it first.
- Installing Fortran and configuring G77 or Gfortran on a Windows XP machine.
- Guide to installing Fortran in Windows Vista Install both G-Fortran and G77 on Windows Vista
If you have a Windows operating system you will probably enjoy using Cygwin to run your programs. Check out Running Fortran from cygwin
 Wrapping Fortran in Python
F2PY is a Python module that allows you to run Fortran code using Python. This can be extremely handy, since there are some processes that Fortran is much faster at, but since Python is much more versatile you can have the best of both worlds.