SBS 2003 Prem w/2 NICs and Linksys firewall

What is the Best Practice for setting up my 2003 Prem SBS w/2 nic cards with a regular Linksys firewall/router?

I’m unsure how how to cable the server which has 2 nics, too the firewall router and Cable Modem.

Further, I also have the ISA program. Am I supposed to install that software on the SBS?

I’m new too servers and need a little advice to keep myself safe online with the server.

I want to allow the server to handle DNS so remote Terminal Services Logins and other functions can be controlled by the server.

Thanks to all.