Change product order (product listing page)

Hi,

This seems like an obvious question but I cannot find a way to order products so the most important ones are at the top of the product and category pages.

When adding a product listing widget to the homepage, which is cool, there is an option to order by product ID, but I cannot find anyway of setting the ID, which is clearly generated automatically. Changing the SKU doesn't have any effect.

I could go into the database, of course and change it there, but is there not an easier way of controlling the order products appear?

Thanks!
Arthur