Routers instantly provide stronger security for your network but wireless is a whole new deal. Wireless transmission instantly opens your network to all kinds of trouble.
Here are tips to help you secure your it.
Change your routers administrator name.
Change the admin password.
Change the network name or SSID from the default to something else. Instead of Linksys name it Freds-router.
Activate WPA2 encryption and create a strong password for it.
Update your routers firmware if you can. Many router manufactures provide very little in updates for your router if it is older plus updating firmware can brick your router. Many new routers update automatically