Of all the 3rd part softwares, none will serve you better than CaptureNX, Alicia, especially if you want to shoot RAW (which you should!). It is the only one that can access a LOT more of the RAW data than any of the other software and take advantage of this. It can do a lot for you for a reasonable $ cost.
That said, its not Photoshop. If someone told me that I could not use Photoshop, I would be VERY satisfied using nothing but CaptureNX and the separate module of NoiseNinja, and still have very impressive pictures.
Welcome to the Nikon camp, you picked an awesome camera!