You should always try The Anime Web Turnpike if you're looking for anything related to anime or manga. It has links to most anime and manga-related sites online. In this case, it's best that you follow Trixie over there; once I spent 16 hours frantically clicking through links trying to find the exit!!
If you're looking for information on the manga industry in Japan, take a look at the Comic Box website, Comic Box is the magazine that covers developments in the Japanese manga industry, but it has been printing some of its articles in English.
Let's not forget all the people who bring us anime and manga! For starters, there's Viz, which brings you the adventures of me and my friends in anime and manga form every month. Also, there is Manga Entertainment, Central Park Media, ADV Films, Animeigo, Pioneer, Software Sculptors, and The Right Stuf, Int.
Speaking of Animeigo, don't forget to enter its Cel Contest, co-sponsored by the Anime Ring, which Jusenkyo is part of.
Also, be sure to drop by the original Japanese companies' web pages, such as Gainax, and Studio Ghibli.