I've got an old book on the Dakota, and if you want to read up on the history of the building and some stories about it's famous occupants you should really get this book!
It's called Life at the Dakota by Stephen Birmingham.
You can probably find it at bookfinder.com
Great pictures, they really cleaned that building. It used to be black from all the dirt in the city. When it was first built it was yellow brick with a copper roof (that turned green later on).