About Freelance Writers offers a wealth of information about the writing business, including sample book proposals, query letters, and more. The discussion forums focus mostly on smaller projects—articles, screenplays, etc.—but also have some discussion relevant to book authors.
Author Zone is a very robust online community for authors, offering personal profiles, discussion forums, private messages, news, reviews, events calendar, and an e-mail newsletter—pretty much everything you could want, all in one place.
WritersNet is by far the most active online community for writers, agents, editors, and publishers. This is the place where professional writers come and discuss the business of writing and publishing books—editors, agents, printing/publishing options, and even wordcrafting.
Ecademy Authors offers conversation of consistently excellent quality, and the networking opportunities benefit greatly from the surrounding context of Ecademy, another one of the largest business networking sites. Ecademy also offers free blogging and article posting, so it's an excellent place to demonstrate your writing skills and create some visibility for what you're doing.
Lit.org is a stylish, well-maintained hub site for authors, offering over 40 different forums, publishing news, reviews, and interviews with writers. The focus here is on stories, essays, poetry, and other short fiction.
WritingForums.com, a sister site of Lit.org, offers 20 or so very active forums on topics including various genres, critique forums, resources for writers, markets and contests, and writing challenges.
The Writer's BBS is one of the longest-running online communities for authors, with over 50 writers' discussion and critique forums, "covering both fiction and non-fiction with topics ranging from poetry to politics, and almost everything in between." The articles and reviews appear not to have been updated in a while, but the forums themselves are extremely active. They also offer a free small web site for members.
Self-Publishing Yahoo Group is co-sponsored by Small Publishers Association of America (SPAN), and is one of the most active communities for authors. Currently monthly volume is over 30 messages a day. Even if you're not self-publishing, the discussion here about the book business and general, and more specifically about book marketing, is invaluable.
Internet-Authors Yahoo Group is a discussion group for authors, both self-published or traditionally published, to share ideas about marketing their books (print or e-books) on the Internet.
Booksigners Yahoo Group offers information and discussion about book signings for authors. This is the place to learn how to maximize the effectiveness of your in-person marketing efforts.
Conclusion
The Internet offers a wealth of resources for authors. Don't forget, though, that it's still about people. Make the right connections, nurture those relationships, and you'll have all the support you need for your book project.
