- Download the Royal Caribbean app. It won't come into play until about a month or two out, but it will keep track of all your ship-booked activities and give you all the scheduled activities.
- Photos are expensive. If you've done Memory Maker at WDW or an unlimited photo package on the Wonder I'd get the unlimited USB package here.
- Your kids will be in the teen club on deck 15. I've heard it's hit or miss. My kids aren't that old yet, so I don't have any firsthand anecdotes for you.
- If you only want one or two specialty restaurants, look into getting a "First Night Done Right" or "BOGO" deal if offered in Cruise Planner. But only during one of those Cruise Planner sales that discount them further.
- The most frustrating thing about the Cruise Planner is that you may or may not see the actual retail price of an item (such as the drink package). If you have your eye on something, make a note of the prices now and then compare when there is a sale.
- Did Symphony have a "Dine Drink Discover" deal for the Boardwalk Balcony? If so, you'll get a couple of soda packages plus a meal for 4 at Johnny Rockets.
- Speaking of which, breakfast at Johnny Rockets is included. I always recommend trying it once.
- Nassau I'd probably walk around the touristy area. If the weather is nice, maybe head over to Junkanoo Beach and eat some of the Fish Fry.
- Coral World in St. Thomas kind of sucks. Avoid anything that includes that.
- If you're just looking to go to the beach, the main strip in St. Maarten is perfect for that. You will need to pay to rent some loungers and an umbrella, but it's not a requirement to get them.
Including some links for you from Matt's RC Blog
First Timer's Guide to Royal Caribbean
First Timer's Guide to Harmony (should be similar to Symphony with a few changes)
My Time Dining vs Traditional Dining
Drink Package
More Drink Package stuff