To
gain an understanding of what the individual hoplite experienced at
Thermopylae and the collective whole known as the phalanx, I highly
recommend Dr. Victor Davis Hanson's 'The Western Way of War & 'The
Wars of the Ancient Greeks'.
While these two books
are all-encompassing relative to infantry battle during the Classical
Greek period, they can be used as excellent references for the students
of the battles of the Greco-Persian and Peloponnesian Wars.