Really good advice in this thread. I'm a Disneyfanatic (stayed on property 16 days once). I agree with WDW over DL as well, more to do, more space in the parks, but I'd also advise that you see DL at least once (including California Adventure which has an awesome Radiator Springs if you have a "Cars" fan.
I also recommend "The Unofficial Guide" for either park. Great information. Not tied to Disney so they tell the truth about rides and most importantly restaurants.
I'm in with the others who say to stay on property. Good lord, I could go on forever talking about the hotels. I'll try to keep it short...
Deluxe Resorts:
Not worth the price by my way of thinking, but worth visiting for restaurants. If your daughter wants to meet characters, make reservations at the character meals. They will visit your table while you are eating so you won't have to wait in line (lines to meet characters can be longer than lines for the attractions). However if I win the lottery, I'm going on a trip where I stay in each one for a week each!
Moderate Resorts:
A good middle ground between price and atmosphere. My favorite is Port Orleans French Quarter (amazing theming) followed by Caribbean Beach (great central location, you can see the fireworks from Epcot and Hollywood Studios from the pool area, but too spread out leading to some long walks).
Value Resorts:
I have no problems with these, they have fun theming and nice pools. I was just looking into going this April/May and room rates are about $105 per night right now. You'll have to wait longer for busses (especially if you stay for the fireworks) but as has been said, you don't spend much time in your room. My favorite is Pop Century because of its location but most people like All-Star Movies. I have not stayed at the Art of Animation yet, it's geared towards families that want a suite, but I have heard great reviews.
Lastly, if you want a reservation at a specific restaurant, call in 60 days early (that's the soonest you can make one) and I mean 60 days before you want to go. Cinderella's Royal Table (the restaurant inside Cinderella's castle) is booked within minutes of the reservation office opening. Seriously my (now ex) wife and I both called as soon as we could in the morning 60 days out. I got a reservation and she was told that it was already booked.