[Tutor] UNSUBSCRIPTABLE?

[WM.]

Traceback (most recent call last):
   File "C:\Python26\TicTacToeD.py", line 165, in <module>
     main()
   File "C:\Python26\TicTacToeD.py", line 150, in main
     DisplayBoard(board)
   File "C:\Python26\TicTacToeD.py", line 68, in DisplayBoard
     print "\n\t", board[1], "|", board[2], "|", board[3]
TypeError: 'function' object is unsubscriptable

I am fooling around with Dawson's "...for the Absolute Beginner". The 
tic-tac-toe program will not run for me. I'm guessing a typi somewhere, 
but cannot find it.

My questions here are;
can somebody tell me, in a general way, what the error message means?
is there, somewhere, a list of error messages with explanations?
is there, somewhere, a dictionary of Python words, such as 
'unsubscriptable'?