I have a router connected to my cable modem. Then I have a switch connected to that router. I have computers connected to the switch. When I look at the list of connected devices on the routers control panel it doesn't show anything past the switch. I have already checked all of the cables and they are all good. Other than that I don't even know where to start looking for the problem. I figured once I got it all plugged in it would just work.
Depending on where you're looking and the age of the equipment, I can think of two good possibilities:
1) Your switch and router are not "Auto Uplink" capable, meaning that you would need to use a crossover cable to patch them (normally yellow, the green and orange pairs are reversed).
2) If your switch was powered on when your router fired up, your computers would fail to get a DHCP lease, and so would not be listed on the DHCP server's connected hosts list.
Your router likely is only intended to route through to a single ethernet port. Does the ethernet port you're connecting your switch to have "LAN" written on it? If so, then you may still be in luck. Otherwise, it sounds like you're still actually in need of a router, that provides a LAN port.
Seems most routers out there have integrated switches and so for those you can just run an ethernet line to another switch and they magically work out traffic routing for you.
I suppose another little thing to keep in mind is if you're dealing with damaged cables, that'll kind of jam a stick in your spokes.