How do I reset the tutorials in Little Big Planet?

If you mean the gameplay tutorials, you can get a basic idea of that through the earliest levels, The Gardens, which will go over all the stuff like jumping/gripping/etc. If you mean the creation tutorials, if you hit Square to go to the Poppit menu, then move to the Tools Bag, then hit Square instead of X in the Tools Bag, you'll see the text from the tutorials you've finished already. If it's blank, then you still need to do the tutorial, which you then should be able to do by hitting the ? mark.