The best way I have found is to plunge them into boiling water for a second or two. Then into an ice bath. The peel should split and come off easily.
Chill whole unpeeled nectarines until semi-frozen (1.5 to 2 hours). Peel with a vegetable peeler.
Freezing Nectarines?
Preventing Banana Slices From Turning Brown
Growing Nectarines
Canning Nectarines
Tips for Cutting Fresh Pineapple
Storing Nectarines