A bit of the repeat from the book reviewing topic, but for indie bloggers, you can look them up by genres they review:
http://www.simon-royle.com/indie-reviewers/ There's a few additional SF/F bloggers on this list:
http://indiesfreviewers.wordpress.com/ with links to other book blog databases.
Right now I mostly follow other indie book bloggers while following SFSignal.com to keep in touch with the non-indie SF/F world. The indie bloggers sometimes end up reviewing the same books (or see the same ones in our inboxes anyway) and it's interesting to see what other people's thoughts on the book are. It's also really cool to see when a review has helped someone out and readers thank bloggers for bringing a book to their attention.