What do I need switch or router

either will do what you want, but the wireless router will give you wireless capability for any other devices you may want to hook up. ipod, ipad, etc. most routers have four ethernet ports on them as well. a switch will be cheaper if you do not care about wireless..

No configuration should be be nescessary for a basic set up. Should be plug and pksy

A switch and a router are not the same. A router assigns addresses and directs traffic to various locations, a switch will not do that. If you do not have enough ports on your router, or are in a remote location with a CAT5/6 cable and need more connections then a switch is used.

If you have a simple modem, one input and one output then you need a router. The router can also function as a switch if need be by changing various settings, but it sounds like in your case you need a good basic router.

http://www.newegg.com/Product/Product.aspx?SID=MtWP5FNqEeKgSy4yW5Zg0gc221_eb6N3_0_0_0&AID=10440897&PID=1225267&Item=N82E16833127436&nm_mc=AFC-C8Junction&cm_mmc=AFC-C8Junction-_-cables-_-na-_-na
$20 done!

This article will also help break it down into simple terms (re: switch/router and what they do)
http://www.smallnetbuilder.com/lanwan/lanwan-basics/31442-how-to-add-ports-to-a-router

Good link!

Very good basic explanation of router/switch setups....

Actually...a switch can contain DHCP and do basic routing.

You should regardless of even if you have a single PC behind your cable modem have some type of firewall device. Routers have additional features beyond the firewall like the ability to port forward and route specific traffic. A switch can handle DHCP and can also route traffic but usually its a per port/VLAN basis.

Assuming your cable modem has a router built-in and DHCP turned on, hook that and everything else into a switch. Location does not matter. Your equipment should find the router just fine and get their addresses from that. If you computer does not do this, then turn DHCP on in your computer. You can also save on running multiple cables to, say, your living room, by hooking a small switch to the one cable to your living room and hooking up a BR player/TV/media player, etc., to that second switch. Saves on running bunches of wires to one room in your house.

So far, in my house, I just upgraded to a 16 port switch in the basement and used the 8 port switch it replaced in the living room and have everything in the LR hooked into that. Works fine.

If you want to add wifi, you can buy a wireless access point and run ethernet to that. You do not need a wireless router if you have one already in your modem.

The problem is we have no idea what the OP has, a simple modem or a router provided by the service provider. So, yes in some cases a switch will work, in others not.