Group items tagged

What's on my Bookshelf offers cataloguing, tags, popular tags, and users can trade books using a points system

Having problem here with thumbnail when sharing, there has to be a solution, and what's with the meta tags, how to get them working properly with shares? 

Librarything allows you to catalogue your books, using amazon searches, the Libary of Congress or other world libaries. Review, and rate these, and share with friends. Import from anywhere. Tag, list by book cover or lists, there are large discussion groups also, an early reviewers club, and LibraryThing widgets to share your book collection in various ways on your blog. Free accounts allow for 200 books. Over this, a small subscription yearly or a lifetime membership is available.

Reader Squared - catalgue, tag, find friends, discuss books and authors.

Listal not only does books, but music, movies, games and more. Tag them, and share with a community.

Book Tribes provides more book lists, groups, sharing and tags.

The blog of teacher and SF writer James Van Pelt. Includes all sorts of interesting and useful advice from a professional.

good blogs on different topics about wiritng