just get a wireless router, linksys or netgear or whatever brand you can find at the store (i.e. best buy, walmart, etc). you can buy it online too if you prefer it that way.
usually has a pretty quick/easy setup, you just plug an ethernet cord between your internet service provider's modem and the router, then connect the devices with more ethernet cords, or wirelessly.
the router will have instructions on how to set this up.