To access, from your home PC, Start>Run>CMD, type ipconfig and look for "Default Gateway". That is the IP of your router.
Open a web browser and enter the IP address into the web address bar.
For your linksys router it should be 192.168.1.1 and your default login is "admin" for the user and "admin" for the password. I am not to familiar with belkins but it should be along the same lines for accessing the web interface.
You will usually find the model number underneath the router. There is usually a sticker with several bar codes. Locate the one the has the model number of your router. You can also go on the manufacturer website and they can usually walk you through the process of locating your model number.