Patterns - ok, click, on say, hats. A few pages of most popular come up, but at the top left, there is a link that says something like "browse all hat patterns" click on that. On the left hand side of the new page has all sorts of search options. Only knit. Only Free. What weight yarn.
Oh, actually, if you just click the patterns tab, there is a link that says "try the pattern browser" and takes you right there - I hadn't noticed before.