I had hair just like that at that age. My mom didn't know what to do with it either. Since I was her first and the only one to have curls she went to my grandma for help since my grandma has naturally curly hair.
I know she used just regular baby shampoo and conditioner for it. I'm sure if you make sure that it doesn't get washed all of the time and use conditioner to help it retain oils that would be the best bet.
I'm 25 now and I don't wash it everyday, but I do make sure that I condition it, otherwise it gets dry and fuzzy.