As SatComer mentioned, you're going to need a router to connect to the modem becauyse your ISP only gives you ONE IP address to connect to the Internet. This one IP can only go to one device, which can be either a computer or a router. That router would then use the IP and connect all of the other devices on your private network through the LAN ports it provides.
Follow what SatComer said and you should be OK. Also, have a look at the following link for some information regarding home routers.
http://compnetworking.about.com/od/r...rk_Routers.htm