The Books We Own Project
http://www.rootsweb.ancestry.com/~bwo/ is a free lookup service hosted by RootsWeb since the early 1990s. Resources are organized by locality (US, Canada and many other countries), surname and general topics (Mayflower, Civil War, Religious Groups, etc.) If you are just starting out in your genealogical research, please check the BWO Tips page at
http://www.rootsweb.ancestry.com/~bwo/tips.html for suggestions on submitting an effective lookup request.
In addition to the BWO project, there is also the Books We'd Like to Own project at
http://www.rootsweb.ancestry.com/~bwo/bowl.html. This site provides a place to list genealogy-related books that you are having difficulty tracking down.
Finally, if you have resources of your own that you would be willing to share, please consider becoming a lookup volunteer! More information is available at
http://www.rootsweb.ancestry.com/~bwo/contrib2.html- Jenny Tenlen
Editor, BWO Project