Promote new book releases. When one member publishes a new book, all members tweet, post, and share the news. You can also share the press releases about your books.
Promote events. When one member speaks at a library, gives a book signing, or offers a free e-book, all members share the news.
Visit each other’s blogs. Each member can do a blog tour by blogging on other members’ sites. This helps... everyone reach new readers.
Blog together. When you create a group blog (where all bloggers post to the same central blog), you may be more likely to attract a larger audience. And all of the blog’s contributors benefit from increased exposure across the board.
Create events together. Put together a group seminar or even a day-long conference. There’s strength in numbers when it comes to PR.