Fat DUX are a usability consultancy.
Their website contains a lot of interesting reading, useful links and a recommended reading list.
I particularly like their web dogma which is "...10 rules that will enhance the user experience of any website or online application."
As well as being very good advice, they steal unashamedly from George Orwell for their 10th rule: "Break any of these rules sooner than do anything outright barbarous."
An altogther classier version of Steve Krug's word of caution about any usability guideline - "It depends" - I think.
The web dogma of Fat DUX