Congratulations on your first Disney vacation - and don't be reluctant! I
know it can seem overwhelming at first, but if you break it into chunks
it will feel much more manageable. I can honestly say that I felt the
same way when I planned our first Disney vacation, but the more I dove
in the more fun it became (obviously - look at me now!)
First I suggest that you determine your budget. This will help you determine step 2, which is selecting a travel date. Prices vary by season, so you may be able to have a September trip that you couldn't afford in December, for example.
At that point you need to determine your length of stay. I generally recommend that guests allow two days each for Magic Kingdom and Epcot, and one day each for Animal Kingdom and Hollywood Studios. If you want to spend time at a water park, Downtown Disney, or just exploring other Disney resorts, add on another day or two (or more - my family usually visits for 10-14 days at a time and I promise you, we never run out of things to do!)
Next, I like to visit the
Parks Calendar Page and note any special shows or parades and times that we might want to see on a particular day, using that to help plan our daily schedule. And finally, once I know where we will be each day, I book our dining reservations. I recommend that you do that very early. Disney accepts dining reservations 6 months in advance and many people do take full advantage of that booking window, so book as early as possible to ensure you get the meals that you really want.
And finally, consider using the services of a travel agent who specializes in Disney vacations. They will be able to help you find the best deals and they will continue to look for savings, even after you've moved on to planning the fun stuff!