Strictly speaking, I do not need a bench power supply as I have been powering the prototypes via RaspberryPi and Arduino power... but a 0-30 volt, 5amp power supply is pretty handy and should make future development smoother and faster. This version is a switching power supply, so I will need to consider noise on the power rails, but otherwise this should be perfect for me.
The middle connector is marked "Ground", but it is earths ground. The two end connectors are (black) negative, and (red) positive. It will take some getting used to, as I have only really used +5V, +3.3V, and ground in my breadboard circuits. Overall, I am very happy with this power supply, 30 volts and 5 amps is more than I will ever need, it is virtually silent, and the output power is pretty clean.
The cables that came with the power supply work well, but I am going to buy cables with banana connectors as well.