You cannot book and travel in the last four months of your use year. If the travel date is within that last four months, you do have to book at least 4 months 1 day out. Other than that I do not think there are restrictions. I have booked a cruise on points over a year in advance and 3 months. As far as the staterooms, I don't know if they only release certain rooms for DVC. We just booked the 6 night pacific coast cruise for next year. We wanted a cat. 9a, but they were already sold out. I did confirm this on the cruise website, so it wasn't a DVC thing. All those rooms were gone. We were able to book a cat.9b guarantee.