Adding a second wireless Access Point to extend a home WiFi network via a network cable

Doing some quick internet searches, this site: http://www.labnol.org/software/add-router-to-wireless-network/19716/ gave me confidence that I could do it.

Basically I also decided to create the secondary access point on a different SSID so I would be aware what devices are connected to which AP. In most cases, I'm not roaming around the house and worrying about transitioning between APs

Steps

Note the settings on the main router

Find the network scheme
So let's say the IP address is 192.168.5.1, mask of 255.255.255.0 and also note that in my case the DHCP is serving up addresses from 192.168.5.100 to 150.

Now login to your secondary Access point.

Leave the basic settings WAN port with all the 'automatic' features (we wont' be using it and this way it won't conflict with the LAN settings we will have to do)
SetUp your wireless settings with a new SSID
Now here is part 1 of the trick
Make sure you turn off DHCP
I picked a fixed IP address of 192.168.5.50 for the LAN setup. It is outside of the main AP DHCP range so it won't ever run into a conflict.

Now part 2 of the trick connect via a network cable to your main AP to your secondary (NOT to the secondary WAN port).

DHCP on the main AP serves up the address to any devices connected via hardwire or WiFi on the secondary AP.