Product Owner’s Rule #1: Don’t do everything alone
Product Owner’s Rule #2: No rush
Product Owner’s Rule #3: Spread the knowledge, use diversity, delegate
Product Owner’s Rule #4: Learn and try new things

http://www.targetprocess.com/blog/2013/02/product-owner-retires.html

How facebook manage code ownership - http://swreflections.blogspot.hk/2013/04/code-ownership-who-should-own-code.html

Product owner checklist - http://larelekman.com/productownerchecklist/