I was proofing a document the other day, but since I've been reading documents from the United States and Canada, I couldn't remember if behaviorial was the American or the Canadian spelling. Thank goodness for Google, I use it all the time to get answers. This time I came up with a site called Karen's Linguistics Issues. It gives the proper spelling for British, Canadian and American words and is very user friendly. It will definitely be added to My Favourites on the side bar of the blog under Spelling. By the way, behaviourial is spelled this way in Canada.
I hope you find it as useful as I did.