This page will discuss getting the whole thing together.
1 Port Router

Connect your cable/DSL modem to the WAN port on the back of the router. It is best to use the cable provided with your modem since it may be a crossover cable. Connect the LAN port either to a PC or a hub/switch. Connect each PC to the hub/switch if one is used. Finally connect the AC adapter to the port marked Power but don't plug it in yet.
4 Port Router

Connect your cable/DSL modem to the WAN port on the back of the router. Connect each PC to the LAN ports on the router. Note that the 1st port and the Uplink port are shared. That means that only one of the two can be used at a time. Finally connect the AC adapter to the port marked Power but do not plug it in yet.