Sharing links to reviews?
Do you mean reviews you've written on your blog or elsewhere? Or other people's reviews?
If you mean reviews you've written elsewhere, check our recently updated Etiquette for Bloggers and Other Journalists ( http://www.chowhound.com/topics/36760... ) for details on when and how that's okay.
If you mean other people's reviews, that's also totally fine and allowed. It shouldn't be the main thing you do to participate on the site, since people want to know what their fellow hounds think, but if you see a good review of a book that you think people who are discussing the book will want to read, then by all means, link it.