do i need a psu? what do i use to control it?
You need:
a PSU of at least 600w bronze per s3. (i'm using a 100w gold PSU for my 2)
and a web browser to go to the ip of the miners for configuration purposes (default 192.168.1.99)
My 500W Corsairs are working just fine. I don't intend to oc, so it's OK that the 500W only has 2 pci-e.