Each book stands alone, although all books in the cycle are set in the same universe.
Works are not numbered as author says: "People write me nice letters asking what order they ought to read my science fiction books in — the ones that are called the Hainish or Ekumen cycle or saga or something. The thing is, they aren't a cycle or a saga. They do not form a coherent history. There are some clear connections among them, yes, but also some extremely murky ones. And some great discontinuities..."