hst is always good, raul duke had some awesome ideas too, but one i would do if i were you would be shel silverstein.
he had a super awesome career, not just his kids books.  he was an acclaimed songwriter (he wrote johnny cash's a boy named sue for one), cartoonist for playboy and one of hef's personal friends, he wrote lots of stuff that wasnt children's poems including plays, short stories and books.  he even wrote a version of hamlet for playboy magazine in rap form.
if you have to do a report on the author, that would be an interesting one that would probably set you apart from the rest of the class.