1066: Year Of The Comet is a free print and play block game (you supply the blocks) about the Viking and Norman invasions of England. It looks terrific.
While nearly every educated person has heard of the Battle of Hastings, not as many know that it was the third of three decisive battles fought in a period of four weeks:; the others were Gate Fulford and Stamford Bridge. Had things gone differently, Hastings could have been fought between Harald of Norway and William the Conqueror. At any rate, this page has some good background and campaign notes for this critical period.
Battle of Hastings is a simple, one page set of free wargames rules for refighting the classic 1066 confrontation between the Normans and Saxons. Reading the rules makes me think that it is designed for use in a classroom setting.
Here’s an article that suggests that the traditional site for the Battle of Hastings is all wrong.