there is alotof ways to achive what u asking for
what kind of access u want for ur servers as u mentioned u want to protect them
so u have to decide what kind off access u want such as http, smtp or ftp
so that u can open only the requred ports for spesific hosts or sources
this is called packet filtring
and about the internet
is u put ur firewall behind a router
make insde and outside interfaces
and make a default route throught outside interface point to ur internet router inside interface
lets say ur router interfaces connected to ur ASA is 192.168.1.1
make :
route outside 0 0 192.168.1.1 1
also make nating lets say ur inside private network behind the firewall is 10.0.0.0/8
nat (inside) 1 10.0.0.0
global (outside) 1 interface
this will do PATing
and the followinf link will help u in configuring ASA
http://www.cisco.com/en/US/products/ps6120/prod_configuration_examples_list.html
Please, Rate if helpful
