Names in bold indicate an expert player. My criteria for "expert" is a world championship, a prominent national championship, and/or writing at a national level.
Ramesh Abhiraman
A blog covering a variety of bidding and play topics, mostly from Bridge Base Online (BBO).
Phillip Alder
Writer and New York Times bridge columnist.
Thomas Andrews
Thomas's Bridge Fantasia includes articles, free software and interesting tidbits.
Andre Asbury
Bridge Maniacs recounts many tournament hands played by the author.
Franco Baseggio
Not regularly updated, but a blog primarily on bidding and play.
Marty Bergen
Leading bridge author ("Points Schmoints"), online lessons, booklets, books, cruises and more. Mention "BRIDGEBUM" when placing a book order to get 2 free softcover books when you buy 1 hardcover.
Larry Cohen
American expert, writer and teacher. Loads of articles. Books and software for sale.
Kitty Cooper
Kitty's website for helping beginning and intermediate players, as well as fellow bridge teachers.
Diyan Danailov
Bulgarian expert and professional. The site includes a few quizzes and blog articles.
Hugh Darwen
Double Dummy Corner is not regularly maintained, but includes many fun double-dummy problems.
Kent Feiler
Writings and an online deal generator.
Marvin L. French
An intelligent set of writings on bidding, bridge laws, squeezes and more by the late Marvin French.
Richard Pavlicek
American expert, writer and teacher. Tons of quizzes, articles, and more.
The best site on the Web for pure bridge content. Unfortunately, Richard no longer updates the site but it's still a trove of information.
Ken Rexford
Cuebidding At Bridge is a blog focusing on intermediate and advanced bidding concepts.
Rod was the original programmer for OKbridge, the first graphical user interface for playing bridge on the Internet. This site is his discussion forum for bridge players in Australia.
Andrew Robson
Andrew Robson's Bridge Club. Articles, online lessons, and more.
Chris Ryall
Writeups of bidding conventions, some very detailed.
7.