Good. It is espically good when you are bulking. It contains essential fats that you need. Also, about a cup of peanuts has about 800cal. Make sure that you get one that has nothing added. The one I use is ground up right infront of my eyes.
peanut butter is awesome for protein. It may have some fat, but if you are working out properly this will not matter. If you are that worried about fat, sure go with straight peanuts, but they still have some fat too. Salted peanuts...ok if you drink enough water to balance out.