What is the waitlist like?? Can I waitlist the whole trip or just certain days??
You can choose. You can do a day-by-day waitlist, where they'll book individual days of your trip as soon as they become available. Or, you can opt for all-or-nothing, where they'll only book a reservation if they can accomodate the whole time.
Which is best for you depends on several factors. Do you mind having to change resorts or rooms in the middle of a stay? This may be required if you waitlist day-by-day and not all days come through.
The advantage of the day-by-day is that you're more likely to get what you want with it.
DVC doesn't hold rooms unless they're booking them. So if you're on the waitlist for 7 days (all or nothing type of wait list) and six of your seven days come available, they won't hold them for you. They'll give them to someone else farther down on the wait list. Then later, if the seventh day came available, you'd have missed out. You could have had the whole week, but didn't get your wait list request because all 7 days weren't available in the system at the same time.
If your desired resort and room type isn't available when you attempt to book, your best bet is to book anywhere you can for the dates you want to travel (as a backup). Then wait list where you actually want to stay. If your wait list comes through, great! If not, you still have a reservation to stay "somewhere." If you don't mind the prospect of possibly having to switch resorts or room types during your stay (which isn't as awful as it sounds), go for a day-by-day wait list. Otherwise, wait list the whole trip.
(One thing to keep in mind is how many points your backup reservation costs as compared to where you really want to stay. If you backup reservation is more points, keep in mind banking deadlines so you don't loose those points.)