Pretty much what 3in2out says.
I don't know of anyone who has been happy with wireless surrounds. Try to find some way to get wires back there, even if you need to go through the basement or attic. You can also run it under the edges of the carpet, or under the baseboards as long as you avoid doorways.
The receiver she chose will handle all the audio decoding, so you only need to connect the HDMI cables from the sat/cable box and BluRay player to the receiver inputs. You will probably need to assign the HDMI connectors to the proper inputs in order to get it working properly. The output goes to the TV. You will want to turn off the TV speakers and let the receiver do the audio work. You will control all switching from the receiver and the TV simply becomes a display device.