so far for me everything has been very simple
just make sure that the solution is high enough that the bubbles continually splash the dangling stems.
if you do that, they should be rooted long before you need to add to the res.
if you're gonna keep it in continuous operation i would change the resevoir solution every 10 days or so.

keep in mind also that you need to monitor the res. temperature (get a little fish tank thermometer at Walmart)
you want temps to be like 70 - 75 degrees (don't be manic about it, you just want the solution to be on the warm side)

anyway, good luck