Any last minute suggestions, I am doing my first square wedding cake next week, and covering it in buttercream, then rolled fondant. Any last minute pointers, on getting the fondant to go on smooth, over sides, and corners without tearing?

Take your time, don't roll it out too thin and raise your cake up so the fondant will drape down and you will have an easier time smoothing it out. Start at the top and gradually work your way down. Not too hard if you take your time.

Don't apply the buttercream thick, just a crumb coat to be sure the surface is smooth.

Also, just in case, you might want to be sure you have access to extra fondant. If you haven't used it a lot, and you have trouble, it will help to have some standing by.

I read it in the (dang can't remember the name of the book) that when you covr a parallelagram (square, rectangle, etc... with fondant that you should start with the corners first and then work towards the middle of each side (at the same time going from top to bottom). that will help with the corner problem.