As someone who's exchanged through RCI before (and have a second exchange coming up in October), here's a few pointers:
First, wait a week or two after the exchange is confirmed with RCI to allow RCI to give your info to Disney.
Look on your exchange confirmation for the DVC Member Services phone number. (If you can't find it, I can look through my info for it) Call them and choose the menu option for RCI. When you talk to the DVC representative, they will confirm your mailing address. They will also ask you for the names of all of the Guests who will be staying with you. Also make sure to ask them specifically for the *Disney* reservation number. You'll need this to link it to your My Disney Experience account. It should be a 12-digit number.
The Member Services rep can also take your flight info and get you set up for Magical Express. This is also the time to have them note any requests on the reservation like building numbers or simply "near a pool" or "close to bus stop".
Now, go into your MDE account. To make your life easier, set up "managed by you" profiles for everyone on the trip *before* linking the DVC reservation. If you have adults who want to manage their own MDE profiles, send them the "Invite to plan and share" friend requests.
Once everyone is set up with profiles, click on the "link a resort reservation" and put in the DVC reservation number. It should link everyone automatically and match up names you gave Member Services to the profiles on your account.
After it's linked, you'll then have access to customizing your Magic Bands. And when you get the tickets from Undercover Tourist you can also link those to your Friends & Family MDE profiles.
I know it *sounds* like a lot, but it's really fairly simple. Your number one thing to make life easier down the road is to get your profiles set up *before* you start linking anything.
-Rob