Getting started in OS X terminal

[Andrew Neil]

I've used a mac for a couple of years now.  Until I found Lilypond,  
I'd never felt the need to dip into the Terminal.  Now I'm keen to  
make use of some features of Lilypond which seem to be accessible  
only from the terminal, such as midi2ly.  I'd really appreciate a  
little help in getting started.
The readme says "Put the lilypond.sh script somewhere in your path, eg.
$ cp lilypond.sh /usr/local/bin/lilypond"

I have carried out this command, but I'm not sure if that is in my  
path.  The following command and output make me wonder:

$ echo $PATH
/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/teTeX/bin/powerpc-apple- 
darwin-current

I've been reading "Unix for Mac OS X Tiger" to try and make sense of  
all this, but it is slow going.  I'm not even sure what a path is yet!
My thanks in advance for any help.

I run Lilypond 2.7.11-1 on mac os 10.4.2, with macpython 2.3  
installed (though it doesn't seem to open).  Python version 2.3.5  
runs in the terminal.