There is no right order. It makes no difference. The only thing you need to ensure is right is that reservoir is directly before pump, and physically higher than the pump, as the pumps don't suck. They have to be gravity fed.
Quote:
Myth: The order of components has a significant impact on temps (eg, the radiator must be before the CPU).
Reality: The order of components makes a difference of less than 0.5ºC in most watercooling systems.
There is only one difference, and that is the position of the pump in the loop, be it before or after the CPU.
Assuming the pump dumps about 50 watts of heat into the water and the flow rate is 1 gallon/minute (gpm - very reasonable assumptions):
Water has a thermal capacity of 4186J/Kg-C at 22ºC and a density of about 1g/mL
With a flow rate of 1 gpm, that's ~3.75 liters/minute (lpm).
3.75 lpm / 60 seconds= 0.0625 liters or kilograms through the waterblocks per second.
4186 * 0.0625 = 261.625 W/C
So that's 1ºC warmer for every 261 watts; but only 50 watts of heat are present, so:
50 / 261.625 = 0.19ºC
Ergo there is a 0.19ºC difference in water temperature between the inlet and outlet of the pump. This does not mean the water is only 0.19ºC warmer than air - that is an entirely different calculation.
And that's with 50 watts. If you're running a smaller pump, such as the D4, you're looking at about 15 watts.
So, do what allows for the simplest tubing runs - tubing length/kinking will have a greater impact on temps.
though not post on the "introduce yourself here" thread (I think) 
