For astronomy, specifically how to find constellations, for kids around grades 1-3 I highly recommend “Finding the Constellations” by H.A. Rey (sp? – the same author as the Curious George books.) My 6yo son loved it this year. The way he connects the stars is a bit different, but actually LOOKS like what the constellation is. (ie, the Great Bear really looks like a bear, instead of a boxish thing with a long tail.) The one thing I didn’t like with this book is that he used English names for the constellations instead of their proper latin/greek/whatever names.
For older kids (and also for adults) for the same type of resource, I would get the same author’s book “The Stars”. Same type of book, same constellation type drawings, just written for an older audience.
Oh – and for the original question about apologia’s astronomy – there is an optional notebooking book you can buy…. and I think there are free journallying pages available (there are for most of the courses…)