rec.arts.sf.written is great because so many fans and writers hang out on this group and it is the perfect place to ask questions. If you've always wanted to remember the title and author of a favorite SF story you read as a kid, this is the place to ask. Before you ask though, it's good etiquette to read and search previous postings first to make sure your question wasn't already answered to.

Once you learn how to use Usenet News, you can find countless subject groups including many writer specific groups such as alt.fan.heinlein, a group devoted to Robert A. Heinlein.

Science Fiction Classics Club at Yahoo