Asterisk - Makefile

Hi there!
I’m really a newbie in Asterisk.
I spent 1 month for research Asterisk 1.4.0 beta (Linux Fedora). Now i’m coming to Compiling function and I get many troubles to understand sourcecode of Makefiles. Somebody helps me please! I list my troubles below:

  • What script is used for Makefile?
  • Organization of Makefiles?
  • If I want to add my piggy-back function to Asterisk, where exactly to place it? (that means what file).

Thank you very much

some info there.