I have a WP blog and naturally it has listings of posts. I have a form where I can select how they are ordered when displayed (alphabetically, date, etc.). The links without and with the parameters in the URL look like: Code: http://www.domain.com/something/ http://www.domain.com/something/?orderby=title&order=Apply OR http://www.domain.com/something/?age=12&size=large http://www.domain.com/something/?age=12&size=large&orderby=title&order=Apply What's the best approach? Should I define a canonical URL on pages that have 'orderby' parameter? Also, I have a taxonomy/category drill-down system in place (like the product categories on amazon.com) and there is a chance that I get different URLs to display the same thing. For example for 'age=12&size=large' query string I might display the same thing as for 'age=12'. Also, what about pagination? Should I even bother about it? I have the titles as 'Original Title - Page 2' but the <h1> title content is the same (Original Title). How much and what should I address myself and how much should I let Google figure out by itself?