I was reading the description for two of the products listed in the link you posted and was wondering what the difference between these two products is:

1. Ubiquiti Networks UniFi AP Enterprise WiFi System
2. Ubiquiti UniFi Long Range Access Point, (2.4 GHz, UAP-LR-US, US Version)

Do you know?

Furthermore, the product descriptions say that setting these up aren't that user friendly. Where's the best place to start learning about basic networking, etc.?

Thanks for all the help.

Maybe try the Ubiquiti UniFi LR - amazon link

I know your wife will hate it, but if there is any way you can get the AP on the ceiling in the hallway between the master BR and BR 1 you will have much greater coverage. Maybe put it some crown molding and hide the cable behind it?

Otherwise, you may want to get an AP with external antenna connectors and get a sector antenna that will at least focus the signal from the existing edge wall inward to your living space.