[Asterisk-Users] Newbie Question

[Leo Salas]

I am just learing some Linux and have been able to setup Asterisk samples 
and channels  fxo card on ch.1 and fxs on ch 4.
I have an Internet Polycom phone to use to test to/from internet and 1 
analouge phone connected to port 4 of Digium TDM-400 with appropriate cards 
installed to dial out on.  I wish to dial to the outside via PTSN line.  I 
am lost on the instructions.  Can anyone help with Extensions.conf and 
sap.conf.   3 extensions are needed.
Thanks for help.
Leo