We currently have an office building with company employees using the our wireless infrastructure.
We are going to start leasing some of the open space to tenants and we are going to offer wireless connectivity. Does anyone know where I can find documentation on best practices and configuration for this type of setup?
Are you going to "share" your AP's with your clients?
You can enable some AP's to broadcast your employees-only SSID and/or tenant SSID using AP Groups (WLAN > Advanced > AP Groups).
One more should be fine. You could experiment with increasing the beacon interval to reduce to total volume of beacons, but I wouldn't mess with that unless you observe problems.
I think 7 is the most SSIDs I've put on one AP, and performance was not noticeably impacted.