If your laptop has wireless card, use that - it should show an icon in the system tray that will find wireless networks within range, then you can connect to your wireless router for internet access. If it does not have a wireless card, you can buy a USB wireless connector, load the software, and connect it to a free USB port on your laptop. USB wireless connectors come in B/G/N flavors. That device will also find wireless networks in range and allow you to connect.
You laptop should also have an RJ-45 port that you can use to connect a standard LAN cable to your router.