Hi,
I assumed you already define the security level for each interfaces (sec0 for outside, sec100 for inside) and changed the status to active/up (use "no shut").
http://www.cisco.com/en/US/products/ps6120/products_configuration_guide_chapter09186a0080636f42.html
1) Configure PAT (single IP) or a range of Public IP within the range assigned by your ISP to be used by internal hosts to access outside/internet.
PAT (single IP) can use either outside interface IP or single unassigned IP from the same subnet.
Example of PAT using outside interface IP:
global (outside) 1 interface
nat (inside) 1 10.1.3.0 255.255.255.0
Example of PAT using unassigned IP (same subnet with outside IP/Public IP assigned by ISP):
global (outside) 1 66.x.x.5
nat (inside) 1 10.1.3.0 255.255.255.0
OR if you have a range of IP, use:
global (outside) 1 66.x.x.5-66.x.x.20 netmask - based on actual netmask
nat (inside) 1 10.1.3.0 255.255.255.0
http://www.cisco.com/en/US/products/ps6120/products_configuration_guide_chapter09186a008063b1fa.html#wp1042339
2) Make sure you have route statement to reach outside and inside interface.
Route to outside:
route outside 0.0.0.0 0.0.0.0.0 66.x.x.x.1 --> example if your internet router is .1
http://www.cisco.com/en/US/products/ps6120/products_configuration_guide_chapter09186a00806403ec.html
3) Optional - Additionally, apply ACL to control outbound traffic from internal hosts
ASA(config)# access-list INSIDE extended permit ip 10.1.3.0 255.255.255.0 any eq 53
ASA(config)# access-list INSIDE extended permit ip 10.1.3.0 255.255.255.0 any eq 80
ASA(config)# access-list INSIDE extended permit ip 10.1.3.0 255.255.255.0 any eq 8080
ASA(config)# access-group INSIDE in interface inside
http://www.cisco.com/en/US/products/ps6120/products_configuration_guide_chapter09186a0080637380.html
Rgds,
AK
