I feed my fry bloodworms but only after I have sliced them up into little pieces (they are frozen bloodwroms... I don't chop up live...ewww). Crushed up flakes work too but bloodworms seem to make them grow faster and my fry love them.
Check your LFS or even Walmart for Hikari's "First Bites" or any other baby fish food. I always feed my fry First Bites, but if not available I just crush up the flake food really fine. As far as feeding amounts just put in small portions gradually. Don't cloud your water..!