For 5 gallons Id use 2 pounds. It may give you more fruit favor than your looking for, but you can always blend it to get just the right flavor (or use 1 lb and risk not getting enough flavor). Dont be afraid to leave the pits, its part of the flavor. Use caution and be aware of the risk of infection from natural yeasties from the fruit (the white dusting found on fruit). Some brewers pasturize the fruit by simmering @ 155 for 15 minutes, or you can use camden tablets. I dont use fruit that often, but when I do, I add it for secondary fermentaion to preserve the delicate flavors.