Although many ASP.net programmers have read these 2 books a few have
not still so I will mention them again.

http://www.amazon.com/exec/obidos/ISBN=0764526413/learnasp
About Face 2.0 by Alan Cooper
and
http://www.amazon.com/exec/obidos/ISBN=0672326140/learnasp
Inmates are running the Asylum by Alan Cooper

http://groups.yahoo.com/group/CooperDisciples/
is where we discuss how to implement superp User Interfaces in your
applications by applying the ideas in this book.

Once you buy the book I recommend reading the following chapters first
and try to improve your User Interfaces or design a new UI using the
ideas within.

Other great resources are
http://www.charlescarroll.com/chaz/site/4146/default.aspx
for books.

http://www.charlescarroll.com/chaz/site/3855/default.aspx
Usability Links

The CHI list is great too....
http://deyalexander.com/resources/mailing-lists.html
has a link to it. But it deals with Nielsen more than Cooper and I
have a list of flaws for Jakob Nielsen's work, so I can't use him as
my primary UI reference guru just as a backup guru for Cooper's work.