asterisk users - Jan 2005 - Need some advises configuring asterisk to call over INTERNET

Hello guys

I just looking for some advises in order to configure my asterisk
server to receive  and make calls over internet, i got a 384 kb adsl
connection.

i just need any information regarding this matter , codecs (installing
g729,g723)
bandwidth, configuring public IP with adsl and others things to keep in mind,

i need anything, so anyone that allready done this please take a few seconds
to give me some advise

Thank You