OK... this may be old news for most here, but just in case...
This has been working for me: Leave the printer on all the time and use printerUtility2 to print out a nozzle check each day. This saves the huge amount of ink used up by "auto cleaning" when the printer is powered on.
Somewhere in the docs that came with the 3800, it said to turn it off is you're not going to use it for 7 days or more...
Best I can say so far is that I've had the printer almost two weeks; left it on all the time; and found that just printing the nozzle check will keep things flowing even thru 3 days of no other prints.