I also just got engaged just over a month ago and a destination wedding is def how we decided to go. I was going to suggest destinationweddings.com since I also just signed up for them and have been working with our cordinator for about 3 weeks. They are excellant when it comes to narrowing down on the final choices. Our situation is a little unique in that we need special handicap accessible venues for the groom's grandmother (who at 80 insists she is coming ) Our DW cordinator has even had a resort measure doorways since they weren;t sure they could be hca! So don't be afraid to ask- they will get the answer for you!
My other suggestion is Destination Wedding for Dummies. The book literally covers everything! And then some!
One other thing to keep in mind is the budget. Alot of these resorts offer packages but for only 10-20 guests. All the additional add-on (guests too!) make things get a little out of control.
As far as a checklist, i suggest you do everything on the regular wedding timeline but add 4-6 weeks on to the send out dates for invitations. Your DW planner will really help you keep things in line and let you know when to have certain things done.
Congratulations and enjoy planning!