Merit - Merit Network is a nonprofit member-governed organization providing high-performance computer networking and related services.
Software Product Management Stack - Resources & tools to help you manage your software product
Eleo - Eleo is an online donor management software.
The Product Management guide - A book on how to create and ship products that people love
ActionSprout - ActionSprout provides tools and training to help nonprofits realize their goals on Facebook.
Product Management Exercises - A repository of product manager job interview exercises