I am going to be old-school and suggest the library. I have wasted far too much time looking for good children's research resources online, though I am still open to suggestions. Many are too simple, cover too few topics, are badly written, inaccurate, etc. Sometimes you do get lucky, but rarely. Also, the average 8yo spends way too much time laboriously pondering web sites that are not the right ones. You don't realize how fast you "weed" as an adult doing web research till you watch a child this age doing it. Yes, yes, I know they need the skill, but in our case this took up way too much time, though DD had to research a vast # of topics for this one project.