Joe,
Sounds as if you have set up the router to provide local Wireless LAN, but haven't set up the router to access your ISP. Best thing is to have a look at
www.belkin.com for their guides and FAQs. I don't use ADSL (cable man, me!). I believe that there are various ADSL settings that need to be entered into the router before it will connect to the outside world.
Other possibilities:
The router isn't configured for (or doesn't support) DHCP allocation of IP addresses to the client PCs. This can be verified by Start/Run/Cmd IPCONFIG /ALL - assuming WinXP/2000. If no DHCP address is obtained, IP address will be 169.254.0.X.
The PCs are set up with static IP addresses / subnet mask / default gateway that do not match the router. Again, using IPCONFIG, check whether DHCP Enabled is Yes or No.
If using DHCP, the router should get DNS server information via the ISP and forward it to the PCs together with the appropriate IP address, subnet mask and gateway address. Obviously these have to be setup correctly in the router.
Example:
Router: Home LAN / Wireless IP address is 192.168.0.1, subnet mask 255.255.255.0. External IP address is whatever the ISP gives it. Router should be configured to act as DHCP server and will need a range of at least 2 DHCP addresses (one for each computer you want to connect). These must be in the range 192.168.0.2 - 192.168.0.254, again with a netmask of 255.255.255.0 and the default gateway of 192.168.0.1. Ensure that the router is configured to forward DNS server info to the client PCs.
For troubleshooting, ensure that MAC address filtering and WEP security are OFF. Once you have everything working, then enable WEP and MAC address filtering (if required).
If you need more help, please say what O/S, and what the IP settings for all the devices are.
SD