congratulations - at least you didnt miss it.
chicks wont need food for at least 24 hours, after that, ad-lib chick crumbs - mum will show them what to do. as for water stick a couple of pebbles in so they dont drown (even if it's shallow, they can still drown apparently!).
cant imagine what the iglu looks like so cant offer any advice on whether or not they can get out - sorry