For ERMAPPER there are two assignments to be done (Assignment_1 and Assignment_2) before you attempt the interpretation exercise (Assignment_VII).
Assignment_1 is derived from the 1st 6 chapters of the ERMAPPER tutorial and is a good introduction to the package. Assignment_2 is a tuturial exercise written by an industry geophysicist to cover the fundamentals of using ermapper to analyse geophysical data and is a good introduction for your interpretation exercise.
Assignment_VII is the main interpretation exercise for the unit.
The erm_intro is an introduction to image processing, please read.
The erm_tute1 and erm_tute2 are the pdfs relating to Assignment_1, ie the 1st 6 chapters of the tutorial book.
Erm_print tells you how to print data within ermapper.
Erm_anno are the instructions on how to annotate maps.
Erm_geophys is information on different geophysical data imaging and presentation techniques and is useful for the main assignment.
Erm_fft is information about various filters you can apply to the data.
Note: that ERMAPPER has extensive on-line help and I have only copied some sections of the manuals to give you an idea of what the package can do.