Sake has slowly seeped through the Internet, having reached a fairly saturating presence there. Any search on the word sake will yield intoxicatingly broad results. A lot of it is good information, some of it is a bit light and some of it is pure business. Here is a quick rundown of what can be culled from the myriad of sites out there.
If neither your computer nor you are daunted by written Japanese, naturally a whole lot more becomes available. A great number of sake breweries have created Web pages, and often they are quite snazzy and informative. Often they show great photographs and images depicting the brewing process and other aspects of the sake world.
The first place to go would be sakewww.sho.ichi.org, the mother of all sake sites. Called the Sake WWW Server page, this is a fairly well-organized list of links to all things sake. Click on the "zenkoku sake map" button and you will see a simple map of Japan. Clicking on any one prefecture will show you a complete list of all the breweries located there.