Go to Guest Services as soon as possible after boarding.
Our "order" is Dining Changes (if needed), Palo ressies, Tea with Wendy tix, spa ressies....then lunch, then enroll kiddos in kid programs.
Remember that you can split up. DH or an older child can get in line at Guest Services for Tea with Wendy tickets while you get in the Palo line.
Please note that there seems to be a big deal on this board about rushing to board and ressies. We've never had a problem getting the reservations we want....but we make a point of arriving at the port no later than noon in order to beat the WDW busses! On our last cruise 2/7/04, we arrived about 11, and were near the front of the boarding line (maybe 150 people back). When we got to the various places for ressies/tix, there were NO lines at all. We just walked up and did our business. We've found that the reservation process has become increasingly efficient over the years!