IMO if you can understand and implement even half of the concepts included in those two resources you're good to go. One helps you make your web site appealing and easy to use, the other helps you speak directly to your customer's needs. Both are also loaded with common sense advice.
Randy, you are 1000% right. A combination of Steve and Karon's advice is a very powerful thing. Steve's book is so interesting, very easy reading and makes total sense. Anyone out there wondering if they should purchase either of these items should do it NOW! I take Steve's book with me on every flight just to refresh my memory and get new ideas.