The
wikipedia article on the CEV is pretty useful. NASA has not yet decided the final design specs for the CEV, but is taking inputs from several companies. You can get more information from each of their product pages. In general, though, the CEV will be a capsule design with either an Apollo-like stack of rockets or Shuttle derived technology. It is highly unlikely that the CEV capsule will be reusable. This drastically reduces the complexity on several issues (especially on how to protect the heat shield).