Well, if you are like me, you might like to visit Keswick and the pencil museum. I am famous for loving bizarre museums and etc, though. It's a cute little town, though, and there's also a graphite mine to investigate (DH is involved in graphene based physics...so we look at graphite mines!). They also have a James Bond museum--(I really do have a tendency to seek out the wacky when I visit a new place).
Other than that, the Wordsworth House etc is nice if you haven't seen it yet (and care about Wordsworth...), and I would definitely suggest finding a few hikes you are interested in.