Fat Cat Brewing Co.
Great sites have to start off with
The Brewery. This is the most comprehensive, readable site for brewing. They have a great Library, and you might want to look at their Links also.Rec.crafts.brewing is a great newsgroup and has to be checked out also.
Brewing Techniques magazine has a great site with lots of info about issues including articles from back issues.
Yankee Brew News is a regional paper that keeps you up to date. Also has Ask the Beer Doctor column, well worth reading.
Storey Publications is a favorite since it's not only a good site to browse for info and published material, but it's located in Vermont.
Suds creator Mike Taylor has a site for his brewing software, which makes recipe formulation a whole lot easier. Besides it's a great name for brewing software.
Check out
Drinkur Purdee Pico Brewery. They have a great classified section for all of those brewing needs as well as a place to sell stuff too.