One more problem you’re going to see when you test: The words users are looking for aren’t there. This usually means that (a) the categories you’ve used to organize your content aren’t the ones they would use, or (b) the categories are what they expect, but you’re just not using the names they expect.
Don’t make me think
Being an expert in online usability Krug gathered his experience in a wonderful book. This summary of key thoughts will help you to remember most important principles and laws.