You haven't provided much information about the requirements or intended setup aside from the fact that wireless is desired. Based on your post it sounds like what you're looking for is a wireless access point. Example of wireless access points:
http://www.staples.ca/en/Wireless-Access-Points/cat_CL200581_2-CA_1_20001
You'd plug that device into your CAT5, and then connect your wireless devices to wifi signal broadcast by said wireless access point. If you already have an internet connection coming into the home, and the home network/routing aspect is already taken care of, then yep, just plug that wireless access point in to one of your available ethernet ports wherever.
Getting a device that is actually designed as a wireless access point may be the easiest, simplest solution, as opposed to just getting a wireless gateway that would require some level of configuration to set it up the way you want within an existing home network. If you're looking for the easiest way, that's probably it.
The biggest consideration would probably to be mindful of wireless disturbers which can be many things, people don't always take this into consideration when thinking their network through - next thing you know, you are their on-call tech support guy troubleshooting wifi issues.
edit: as for what particular make and model: i wouldn't pay too much heed to brand loyalty. Research the specific model carefully and buy on price once you've narrowed it down to a couple of solid options. Pairing similar chipsets between AP and client devices tends to give best results to avoid any incompatibilities.