I personally book with costcotravel.com. When I was new to
DCL I read here and I read on cruisecritic, and never needed to ask a TA many questions at all. So I book with the place that gives me the best deal, and the giftcard mailed after the cruise is the best deal I have found.
Advice: when you get onboard, when you get your Navigator (the papers that tell you what's going on), read it! Cover to cover. Take the time to do so, because it will save you time later.
I will put everyone on meds before we leave etc..
Remember that nowhere near everyone gets seasick, and that those drugs DO have side effects!
If taking a Bahamas cruise, that first night crossing the Florida Straits can be bumpy as anything, but in general, that's the worst night. Have dinner, see a show (or vice versa), go to bed. Wake up to what should be a lot calmer seas.