Paginated content includes things like an article that spans several URLs/pages, or an e-commerce product category that spans multiple pages. With rel=”next” and rel=”prev” markup, you can provide a strong hint to Google that you would like us to treat these pages as a logical sequence, thus consolidating their linking properties and usually sending searchers to the first page.
Pagination Introduced : Pagination with rel=“next” and rel=“prev”, Thursday, September 15, 2011 at 5:00 AM
Link : http://googlewebmastercentral.blogspot.in/2011/09/pagination-with-relnext-and-relprev.html
Read updated article : http://googlewebmastercentral.blogspot.in/2012/03/video-about-pagination-with-relnext-and.html
How to implement Pagination in your website : http://support.google.com/webmasters/bin/answer.py?hl=en&answer=1663744
Also view the Youtube video on rel=prev and rel=next , Pagination for long blog pages:
The Pagination Slideshow by Google :