First off, here are a few links to the sites I visited daily. There was so much helpful information on these. My first and favorite was,
My First Visit. If you are planning a trip to Disney, there is so much helpful and detailed information on this, that you will feel very informed and it will help you make a lot of decisions more easily. This was my favorite website, by far.
The other two websites were also very helpful in planning which parks to go to on which days.
Touring Plans and
Undercover Tourist. I also bought a book from Touring Plans called "The Unofficial Guide to Disney World 2012" that was very informational.

My first tip: Wait until your children are old enough to actually enjoy it! You'll enjoy it better that way, too! I can't tell you how many articles I read before leaving about scheduling nap times and what kind of stroller to bring and what to pack in the diaper bag, cooler, and backpack. And I AM SO GLAD I DIDN'T HAVE TO DO ANY OF THAT! My kids don't need naps. And they don't need strollers. And we didn't need to fill a diaper bag with all that stuff that little kids need. I understand why you would want to bring your small children to a wonderful place like Disney World. There were so many times when our kids were little that we would see other families going and it made us just a little jealous. But after being in the humongous crowds and seeing all the crying children and frustrated parents, I am SO glad we waited. Let me be honest. We live 14 hours away from Disney World. This trip was our first, and maybe the last. It was expensive. I wouldn't want all that money and all the planning to go to waste by taking little kids that won't remember it.
All we took was a cinch bag that was lightweight and able to be carried on my back. It had an outer pocket for easy access to tickets, money, and the camera. Inside the bag, we kept clear plastic ponchos (in case of rain), wet wipes, kleenex, hand sanitizer, a couple of bandaids, some tylenol, a water bottle, and some individually packed snacks. That's it. And you know what? We were fine. Another advantage to this is that they check every bag before you enter the park. I felt bad for those families waiting in line while their stroller, diaper bag, backpack, and cooler was being checked. I smiled and waved with my little cinch sack as I passed by them (not really).
My second tip: Buy your tickets from Undercover Tourist and don't buy the park hopper pass. The only reason I could think that the park hopper would benefit you, is if you were visiting a park for the day and had reservations for a meal at another park on the same day. But for us, one park a day was all we could handle. It made for a lot less stress. Undercover Tourist is trustworthy and is one of the only sites I found with tickets at a good discount. Saving money anywhere you can is good. Also, the longer you stay, the cheaper your tickets (per day) are.
My third tip: Stay on site. Stay on site. Stay on site. Is it more expensive? Yes. But SO worth it. If you can swing one of the resorts on the monorail, do that. Do it.
My fourth tip: Do the dining plan. Trust me. If you are really wanting to save a lot of money and want to avoid doing the dining plan, I suggest skipping dining at Disney altogether (maybe with the exception of a character meal or two) and plan to buy/bring groceries. It would be very easy to have breakfast, lunch or dinner at your resort. Or pack a cooler to take to the park for meals. We had a refrigerator in our room, but not a microwave. However, I read somewhere that you could request one and they'd put one in your room. HOWEVER, if I could do it again, I'd do the dining plan. Hands down. We felt like every meal, we were pinching pennies and ordering the cheapest meal we could to save money. With all the amazing restaurants in Disney, we really didn't eat all that great. If we had gotten the dining plan, it would all have already been paid for and we could have eaten a lot better. What would be a great option, would be to plan a trip when they offer a free or discounted dining plan.
My fifth tip: Plan some down time. Whether it be one whole day or a few hours in the afternoon of each day, plan it. The resorts have so many fun things to offer, that the kids really wanted to do some of those things, too. You don't have to spend every minute of every day at the park. You'll hate yourself after about the third day, if you do. Contrary to popular belief, there is such a thing as Disney overload!
Lastly: Plan accordingly, but have fun! I am a major scheduler. This trip was a scheduler's dream! I planned which days we would go to which parks, according to the crowd calendars I found on the above websites. Then from there, I planned which rides were a "must see" for us. I had planned on following the itinerary given in the "Unofficial Guide" but in the end, we just did what we wanted. One thing I wish I had been more careful with was the Fastpass system. I would forget to get a fastpass for a particular attraction, and then by the time I remembered, the fastpasses were already used up or the return time for our fastpass was so late in the day, that we would forget about it. So, don't forget to get your fast passes first thing! I did read they are coming out with a new system soon that is supposed to be even more convenient. The thing for us, is we would be too lazy to walk ALL the way over to one side of the park for a fastpass, then walk ALL the way to the other side for the current attraction. That is a lot of walking!! We would try and cover sections at a time, instead of zigzagging all over the park. Call us lazy, but that is what we wanted to do.