Router Ethernet Question

[Phool101]

Hello,
I'm new to networking and I am planning to switch from wireless to a wired connection because of stability issues. I'll try to make this as clear as possible for my situation.
I have a router with internet access a floor below me and I'm planning to drill a hole where I can thread a Ethernet cable from downstairs to my floor. The first jack E1 is occupied (from the modem; internet). Will plugging an Ethernet cable on the second jack E2 grant me internet access if I plug the other open end to another router/switch? (I don't really know the difference between them.)
My main question is, do I need to buy a switch or a router? Because I would like to also have my other devices such as my PC and PS3 to be hardwired.
Are there other configurations to the existing router I need to change?

Pictorial

Modem <Ethernet> Wireless router <will it work? if... Ethernet> Router/Switch <Ethernet(s)> Devices.

If it's too complicated, I'm sorry and I'll try to restate my question. :\

 

[jankyscoes]

Install a switch and you wont need to do any additional configuring. Everything plugs into the switch and then one cable runs from the switch to the router. You could use a router instead of a switch, but you would need to disable DHCP on the second router

 

[Phool101]

Hmm, okay sounds simple enough. What is DHCP? And what will happen if I don't turn it off on the second router?

 

[bill001g]

DHCP is what gives your PC IP addresses. Having 2 of them means both attempt to give out IP addresses which generally leads to multiple machines being given the same IP which does not work.

 

[jankyscoes]

Check here for more info on how to setup 2 routers on the same subnet.
http://www.tomshardware.com/forum/33700-42-ultimate-modem-router-setup-thread

 

[Phool101]

Best answer selected by Phool101.