I've never used a TA. Go get yourself a book on WDW. The Internet is amazing but a lot of navigating. The Birnbaumbook has photos and tips/ideas. You can read and compare resorts.
My recommendation for first time on a moderate budget:
Stay at Port Orleans - great pool, wonderful grounds, love the boat that takes you to the Disney Marketplace (where'd I'd make a reservation at the Jurrasic Park restaurant - forget the name).
My MUST meals are dinner at 1900 Park Fare (with Cinderella,prince, godmother and stepsisters), breakfast at Crystal Palace (Winnie the pooh and others), breakfast or dinner at OHana (making sure to stroll the grounds of the Beautiful Polynesian resort), and of course Le Cellier if it's available at EPCOT.
My MUST dos while there: strolling the boardwalk in the evening for desserts and entertainment, catching the beachside movie or campfire at Beach Club, ice cream at Grand Floridian, night vision glasses at Animal Kingdowm lodge, and a round of mini putt at Fantasia golf.
Have fun planning.