I'm working with a local business to upgrade their WiFi coverage. They chose to install a Ubiquiti Networks UniFi solution. It consists of multiple APs each cabled back to the main switch. The system is managed by a free Ubiquiti app that allows you to configure each AP, see traffic and users on each AP, etc. For our installation, all of the APs use the same SSID and passphrase.

You might think this is a pricy solution, but the individual APs cost only $70 ($90 for a long range version.) And the management app (Windows, Mac, and Linux) is free. It's really a terrific system.

Take a look at: http://www.ubnt.com/unifi/unifi-ap/