Salt is a good stress reliever. I like to use it with all new arrivals. 2 tablespoons per 10 gallons. Keep the lights off only for the first day and then turn them on. If you baby them too long then get shy whenever they come on and you don't want that.
Move slowly around the tank for the first few days until they get used to you. Once you feed them a few times and get them to associate you with food, they'll be at the glass begging in no time.
I always ask the seller what they were feeding so I can give the new fish familiar foods. If you have access to live foods like Blackworms (not tubifex), they are a great way to get your fish eating as well. Also, raising the temperature a bit (88 degrees) will get their metabolism going and will often get them eating faster.
hth
-Ryan