Welcome Tectrendz. There are a couple of methods to handle this if you are using a static IP.
If all inbound traffic is destined to the server then yes you will assign the public to the WAN interface on the WRT54G2 and set up a 1 to 1 NAT rule on the Firewall to route the traffic to server. If you have other devices that are behind the WRT54G2 that require remote access then you would create port forwarding rules that sends the traffic to each device. Let us know if you require further assistance.