Wet kitten food is best, but dry can be fed, also. As long as the food has plenty of meat in it and no cereals, grains or corn in. For young kittens, soft food will be easier for them to eat.
Cats are carnivores so they derive all the nutrients from meat, so it makes sense to find a food with a high (50% or over) meat content. This should be the FIRST, or first couple of ingredients (listed as Chicken, Turkey, Lamb, Tuna, etc.). Foods that are free of grains, corns, and wheat gluten are highly recommended as these are cheap "filler" that bulk up foods - but have no nutritional value for your kitten. Wet food with these specifications are much easier to find than in dry food.
Kittens are constantly growing and developing, so they need all the nutrients they can get. Typically, a kitten will need twice as much protein as an adult cat, so it is usually best to feed the kitten as much as it needs until it is around a year old.