how do you connect to the internet?
how do you connect to other computers in the LAN?
do you want to set up a computer in your home LAN?
if so, 192.168.11.n will do (n=1...254).
netmask is then 255.255.255.0
you probably won't need to use a gateway.
is your computer connected to a company/university LAN?
in this case you have a good chance to be able to use DHCP instead of static IP. if that doesn't work, ask the administrator.
read more about linux networking here:
http://www.tldp.org/HOWTO/Net-HOWTO/