It looks like everyone has given you some great tips already, so I'll just say I never stayed at the Grand Floridian until a couple years ago. When my late wife and I got married and bought into DVC at the Animal Kingdom and when we realized how far away AKL was, we bought at Grand Floridian and absolutely loved it. I personally never wanted to stay at GF, it never seemed as fun to me as Poly, and always seemed really spread out, but it was amazing. To me, it may have the best staff at any hotel in WDW. You have 5 sit down restaurants plus the afternoon Tea area, I'm a huge Tea drinker and we did this the first time we ever stayed at GF. You have a small, but nice quick service area. There are a number of shops. 3 bars if members of your party enjoy an adult beverage or 2. Due to the lobby being so large, it is one of the more relaxing lobbies in WDW. You are just a monorail stop away from MK, you can take the monorail 3 stops to get to the TTC and head to Epcot or walk through the Polynesian which is also a very short walk away. Overall, you just have a lot of options, nice rooms, great location, and amazing cast.
One mistake I see people make is they think you can walk from MK to GF, but you can't. I see 1 or 2 families every night after park close who see the boat is packed and the monorail is packed and they start walking down the walkway towards the GF.