Add ethernet router to wireless network

Hello all you smart people out there,

I'm trying to expand my network... short version is that I got a device (Airave) from my wireless phone carrier (Sprint) that's supposed to boost the Sprint signal that I get in the house (I get no signal inside at all).

The Airave is supposed to plug in directly to the DSL modem. The problem is that I only have one outlet on the back of the DSL modem (an older unit, provided by Windstream).

Before I screwed it up it was set up as follows: DSL Modem>Linksys Wireless Router>and then connected to the Linksys via ethernet were a desktop computer and a hardwired older Buffalo wireless router (to extend the wireless network), and various wireless devices as needed (smart phones, laptops, Kindle, etc.).

So, I purchased an ethernet router (not a switch) to connect to the DSL modem to give me more ports. (There are also 2 LAN ports on the back of the Airave, unused for now.) The current order of devices is DSL Modem>ethernet router>and coming out of the ethernet router are the desktop computer, the wireless router, the Airave, and a spare ethernet cable to hook up to the laptop since the wireless isn't available.

And now the wireless is not working. Everything plugged into the ethernet router works, I can get out to the Web, if I'm hard-wired.

So, two questions, really:

1. should I have gotten a switch, and

2. if not, what order should these items be connected to each other? Both the Linksys wireless router and the ethernet router have the same IP address--which may be significant as well.

(As an aside, does anyone have any experience with Best Buy's networking folks? Should I just have them come in and setup/fix my network?)

Please let me know if you need more info. And THANK YOU for your help.

Why don't you just plug the Airave into a local port on the Linksys Wireless Router? If you ran out of ports, you need a network switch.