[PD] command line question

[Alex from Idoia]

Hello,
I am on Mac OSX and I have been using the terminal for a couple of 
months now as it is the only way to get pd to work.
At the beginning I had some difficulties to install it and I have 
simply downloaded the package version of pd+tk of Adma Lindsay which 
installed everything for me. Now, I have a bit more knowledge of 
terminal commands and as I have downloaded some externals from 
pure-data.org, I wanted to try again to install them myself. I get 
stuck to the particular commands where I have to type make clean then 
make and finally make install.
My terminal tells me 'command not found'. In any hope of discovering 
something by myself, I noticed the Makefile file in some external' s 
directories and try to type ./Makefile then I got the answer Permission 
denied(as superuser). I understand that has more to do with OSX/Unix 
language and less with pd itself, however I am sure many of you can 
help to answer my newbie questions. Also any reference website to learn 
a bit more about the command line will be most appreciated.
Thanks a lot