Hello Lisa,
Welcome!
I did not go to WDW until I was over 40 when I went for my honeymoon (I got married late) and did not go back until we went with our son when I was over 50 (you cannot believe how hard it was to type that last sentence, and yet I digess). I did not become a WDW junkie until the first trip with my son I think it was that up until our first WDW trip other family vacations didn't appeal to me and just left me more tired between driving, worrying about our bags and where to eat and would there be enough to keep our son amused and interested etc.
To answer your question it depends on what you like if Yellowstone and nature are your thing then go, If you are interested in WDW I would recommend doing some research to see if that is what you want.
There are many tour books; if you go to a bookstore you will find about 3 shelves of books on WDW alone. My personal favorite is the Unofficial Guide to WDW. The complete edition is about 1300 pages and covers the entire Orlando experience including Universal and Sea world. There are several “spin-offs” of this book also, including the unofficial guide with children, without children, the greater Orlando area minus WDW, and the Mini-Mickey edition. This is a pocket sized version. I recommend the complete version as it will address just about any question you have. You can also usually find this book at your local library but it might not be the most current edition, it should however still be very useful and relevant.
There are also many websites, in my opinion the best for planning is this one and allearsnet.com, thiese websites contains just about everything you need to know about WDW, Disneyland and Universal. The parts I find most useful are the accommodations and dining sections. There are reviews and slideshows for every Disney resort as well as reviews and menus for every restaurant, including fast food and snack carts.
Good Luck
