Yes... I've found best way to add fruit is to secondary and rack beer onto it after primary fermentation is complete. Remember fruit has fermentable sugars in it so when you add it, it will kick off another round of fermentation. Give it about 5-10 days on the fruit then package. I agree w the 1 lb per gallon which will impart a significant fruit flavor.
With cherries, consider using a mix of sour(tart) cherries and sweet cherries so it doesn't turn cloying or sour.