Also check out ravelry.com (free to join) where you can search using your yarn type (weight, fiber content, and amount), as well as other helpful criteria (whether you want to make something for a male or a female, age-appropriate items, construction--fair isle or in the round, for example, etc.).
Ravelry is much easier to navigate than the Pattern Central site because you can see pictures of completed projects on Rav. I sometimes get annoyed with having to click all the links on Pattern Central. But, by all means, check out both!