Welcome to the Network forum.
Technology wise the solution is to buy an Access Point, plug it to the open port on the Router, set it up and done.
However Access Points are more expensive than Cable/DSL Routers.
So you might want to buy a New Wireless Cable/DSL Router to replace your current Router. Or you can configure the Wireless Router as a switch with an Access Point and plug it into the Netgear.
The following pages might help:
Link to: Wireless Cable/DSL Router or Access Point – What should I get?
Link to: How do I use a Wireless Cable/DSL Router as a Switch with an Access Point?
Link to: Wireless What Should I Get?
Once you get the Hardware:
Link to: Wireless - Basic Configuration.
Link to: Wireless Security.