How To's
First and foremost, to have a complete and detailed description of the system, read the wiki page dedicated to CCMS Blackhole cluster (http://www.mech.uq.edu.au/hpcwiki). For the login and the password, read the email you got from the admin when your account was created.
Installing FFTW (2.1.5)
Load PGI (7.0-2) and OpenMPI (1.2-pgi-7.0-2). They are the default modules. The installation process is basic: ./configure/make/make install. You may install FFTW with single and double precision.
./configure --prefix=/MyDirectory/FFTW-2.1.5 --enable-mpi --enable-fortran --enable-threads --enable-type-prefix --enable-float
Note the last flag (--enable-float) is for single precision. You can add the options F77, CC, FFLAGS, CFLAGS, CPPFLAGS and LDFLAGS to relate to compiler commands and flags if configure cannot find them. In this case, they would be (for the versions of the module cited above):
F77=/opt/openmpi-1.2/pgi-7.0-2/bin/mpif77 CC=/opt/openmpi-1.2/pgi-7.0-2/bin/mpicc FFLAGS=-L/opt/openmpi-1.2/pgi-7.0-2/lib CFLAGS=-I/opt/openmpi-1.2/pgi-7.0-2/bin CPPFLAGS=-I/opt/openmpi-1.2/pgi-7.0-2/include LDFLAGS=-L/opt/openmpi-1.2/pgi-7.0-2/lib
You can always try ./configure -help to have more details on the options.