Anne Kowalski

Excellently written. I really recommend this book to anyone that creates visual interfaces for websites or web portals. Along with the theories and examples of web usability, there's instructions on how to do usability tests as well as how to sell usability to bosses and clients.

There are a lot of similarities between this and Information Architecture for the World Wide Web.

One of the best parts of this book is the recommended reading. Krug gives summaries of the books he recommends, along with ISBN/publisher info.