Main netcdf page http://www.unidata.ucar.edu/software/netcdf/
Programming with netcdf:
General programming tutorial http://www.unidata.ucar.edu/software/netcdf/docs/netcdf-tutorial.html
Matlab http://mexcdf.sourceforge.net/ (in matlab by default in versions >= 2008b)
Fortran 90 http://www.unidata.ucar.edu/software/netcdf/docs/netcdf-f90/
Fortran 77 http://www.unidata.ucar.edu/software/netcdf/docs/netcdf-f77/
Java http://www.unidata.ucar.edu/software/netcdf-java/
Python http://www.pytables.org/moin/PyTables and http://www.scipy.org