I want to set up 3 ARs in a single home (large home) with one acting as the main router and the other two acting as extenders.

There is cat5e running to the other two locations from where I want to place the main AR. The main AR will be where the structured wiring can is.

I also need connected devices to be connected to the other two ARs for wired devices, like desktop computers, as well as wireless devices such as cell phones, tablets, etc.

The residence is quite large as one AR will not cover even half of the home.

I am hoping for an easy way to set this up and any help would be appreciated.

I would opt for 1 router & access points instead. Some prefer wired only router and all access points. The ubiquiti unifi ap's have been good for us. They support zero handoff roaming so wired router and 3 unifi ap's could be a good design. For those locations needing hardwire, use a switch.

Hope this helps.

How large and how often do they need WiFi in all locations?

If you want the most flexibility/control, use:

Modem-->Router--->Main area
\-->Switch with WAP
\-->Switch with WAP

The switches don't need much/any setup and the WAPs can be set for the power level dictated by the location. If they need to maintain connection without dropouts, use one WiFi and hard wire what can be/works best when hard wired.

Keep the layers to a minimum- Modem is one layer, router is one layer and anything plugged into the router is another layer, so the switches should be on the same layer, especially if they need to access other equipment from various locations. If you can home run multiple ports from all of the possible locations and place one large switch near the head end, you can connect all of the devices AND WAPs to the one switch, which allows you to use only three layers (Modem/router/switch).

I didn't think of using 2 switches where the other 2 ARs will go. I have a 8 port switch where the main AR will be, so I will get two 4-port switches and plug the other 2 ARs into them.

Seriously, just use one air router and as many unifi Al's as you need. That will give you a stable network and great coverage and provide the best user experience.

If you need the wired connections at each AP, you can use the bridged feature of the Unif APs and plug a switch into the ap, or you could just use a switch at each location and run the APs off the switch. The only way I would do two routers would be if I needed two networks. I would look at the ERL for the can, then however many UAP Pros you would need. The UAP PROS are my ap of choice if the client doesn't go for Aruba....which costs twice as much.

I would definitely shy away from using more than 1 AirRouter. A network should really only have 1 router/gateway. You can configure routers to be access points but it makes your life that much more difficult and when/if the router was ever factory reset, it would wreak havoc on your network because you would have multiple DHCP servers and clients on one router would be disassociated from other clients on other routers.

Add to that the fact that Ubiquiti already has above average solutions intended exclusively for what you are trying to do and I see no reason why you should be using multiple routers.

Unfortunately, I wasn't the one who sold the equipment. They actually have 4 ARs in the house.

I wound up using one AR as a router which connects to a 8 port switch. The other 3 ARs are plugged into the switch, with other hardwired outlets, which are running in AP and bridge mode. Everything works great.

I set them all to the same channel. Was this a good thing to do? Everything works really well.

You need to alternate channels, 1,6,11.

Unless he is using "zero handoff" in which case all APs operate on the same channel.

You can turn off the routing in the airrouter and just make it a bridge with an integrated AP.
You can even make the WiFi on the airrouter act as a station device for areas where you can't run a wire.

The current design is a really poor design and layout option, even if you know what you are doing with the hardware. It's going to be a PITA science project that you will be giving free service calls on for years.

Offer them a "trade in" on the 3 AirRouters and put in UniFi for WiFi and use 1 AirRouter for LAN/WAN.

Just having them doesn't mean they have to be used.

No, but that was the only way to get even coverage throughout the house.

I had to play with the power output so there wasn't as much interference between one another. They previously had 1 hard wired router feeding 2 APs and they were constantly getting weak signals and dropouts.
Think of the house like a cross, the kitchen on the long end while the play area was on the short end with the master on one wing and the guest beds on the other wing.

So far everything works well and I had to also connect their AT&T Microcell unit. Pain in the butt that was.