Maybe more inspiration than introduction, but the "Game of Life in APL" video is a must see (http://uk.youtube.com/watch?v=a9xAKttWgP4&fmt=18)
The description on YouTube points to a "Game of Life" tutorial at http://tryapl.org. I haven't tried it, but it looks nice.
For a more academic (as in "read about, don't play with") introduction, I found Iverson's "Notation as a Tool of Thought" (http://awards.acm.org/images/awards/140/articles/9147499.pdf) a good introduction.