Router
More information to come later, but at a minimum:
- Ensure you are using at least WPA2 security, not WEP or WPA
- Disable UPnP unless explictily needed - this services allows anything on your network to open a firewall port on the router
- Disable WPS - as its PIN can be hacked wirelessly in hours, giving full access to your wireless network
- Ideally, if your router supports it, create multiple wireless VLANs - 1 for your regular devices and another for untrusted devices that only need internet access such as TV or thermometer