Lots of info on the post located at the top of this forum. It is called the Swan and Dolphin FAQ.
I love the Swan. It is my fave WDW resort. I have also stayed at the Poly and the CBR. The Poly is also way up there, but the Swan beats it only because of convinience to more parks, and transportation options.
The Swan is much smaller than the Dolphin, and that is a great big plus at the end of a long day. Bot the Dolphin and Swan are themed the same once you are in the rooms(and all rooms are renovated) The rooms at the Swan have two queen beds and a sink inside and outside of the bathroom which is a big plus with families. The pool is a little farther walk from the Swan than the Dolphin. The Swan also has much better views, just because of where it is situated. From one side you can see Illuminations fireworks(those in the air, not those near the water) and from the otherside you can see from some rooms Fantasmic!!!
If you have any questions not answered in the FAQ just yell