Sounds like you've never been to WDW and this is a big trip. You will have a lot of fun, but doing up-front planning and research is key to a good time...........Have to agree with you.....up-front planning and research is very much key to a great time!!!.........
I will first suggest that you determine a general park plan (one park per day, hopping, etc) and what park(s) you expect to visit. You can find historical hours/showtimes on the internet at a variety of sites. Then, figure out where you want to eat in those parks as you can make reservations 180 days in advance. Hotel dining is terrific and well-themed too............see my first posting regarding the reading!!!
If you like sit-down dining but want to mix it with counter service, the dining plan is a great option. There are some benefits and some drawbacks, but for two adults it is likely to be a good deal. Just figure out where you want to eat, take a look at prices, and decide whether or not it is for you. I don't like it as much with kids because they just don't always eat. For two adults, it should be worth it.
Basically, the plan is $40 (2009 price) per person per hotel night. You get a sit-down (table) meal, counter fast-food meal and snack each day. It works like a debit card and they just deduct as you go so you start with the total until they are gone (no per-day use restriction). Gratuity is not included. So, $40 really isn't much for 2 meals and a treat (ice cream mickey is something like $4). Alcohol is not included, but soft drinks, meal and dessert is included in most meals. If you use the dining plan to your greatest advantage (table for dinner always, counter for bfast/lunch) you will get the best deal.
There's so much to learn and plan - have fun with it. I can't stress enough the need to outline a plan and make table service dining reservations - that will really help you enjoy your trip to the max!