These two (printed) books have been available for years and have become standard reference books for thousands of genealogists. The books are thick, packed with material, and expensive
Ancestry.com recently sold its book publishing business to Turner Pubishing. See my earlier article at http://blog.eogn.com/eastmans_online_genealogy/2010/03/ancestrycom-sells-book-publishing-business-to-turner-publishing.html. However, it appears that Ancestry.com retained rights to publish at least some of the materials.
Ancestry.com now offers online versions of these two books in a wiki format. These two online offerings presently contain every word of the latest versions of those books. Unlike the paper versions, the new online versions are searchable by every word. Even better, these previously-expensive books are now available online free of charge.
This wiki features a "living version" of the company's two largest reference books. These books, which are exhaustive guides to American genealogy, will now be made available for the family history community to update, expand on and even add to, making it a go-to resource for guidance and information. In other words, you and everyone else can contribute new or updated information to these books. (There will be a review process before new information becomes visible to others.)
The beta version of the Ancestry.com Wiki is available NOW at no charge at www.ancestry.com/wiki.