Asterisk conf. files

Hi all.

I have just installed Asterisk on a fedora core 4.

Now need to begin my first steps with Asterisk … can someone help me with these assistance:

I was able to ses:

"sip.conf " in /etc/asterisk; is this directory the place where I should all files for asterisk to see and operate with ?

Do I need to create a child directory and place all my files ( sip.con, exten.conf, etc… )

Or I should just modify the ones in /etc/asterisk to see and operate with.

Will a creation od a new directory located somewhere will ever be needed ? or the just modifying the files in the existing directories will be just fine for all setups ?

Thanks very much for your help.