with a bit of thinking and some grunt work you can even produce your own perpetual motion power plant. I'd suggest reading about screw pumps in the wiki as they explain how to set up a pump stack as it does take some careful removal of floors to make sure power does go through the stack.
for powering a stack, the power has to attach to any pump within the stack itself. As long as one pump is connected to a power source that provides enough energy, all of the pumps will be.
With pump stacks you can connect them either from the side or the top. If you try to power it from underneath, it will result in your stack being listed as hanging, which will result in the entire stack collapsing. this can be resolved by having another connection to the stack that keeps it stable (ie a gear or a wooden axle)
for pumping remember that once the power is turned on you will not be able to stop the pump unless you remove the connecting axles/gears that provide power, or you link a gear to a lever which allows you to dis/allow powerflow through the gear. this is important especially if you discover a leak in your line which can result in alot of Fun.
also with water wheels, if you do have a gear linked ot a lever, make sure that the waterwheel is supported by something else other than that gear. Otherwise when you turn the gear off you end up deconstructing your water wheel.