Steps of Justice - Prayer Guide is a great little resource...and it's free too for the pdf download.

This is the blurb:
The 30 day Prayer Guide:
Steps Of Justice began from the injustices that missionaries with Youth With A Mission would see while travelling the world sharing the love of Jesus. No matter where we were in the world we would see injustices like, slave labor, child prostitution, unclean drinking water, lack of opportunities for education, lack of medical care, overwhelming poverty, corrupt government, etc… A group of us have asked ourselves what can we do? Then we prayed asking the same question “Jesus what can we do for such overwhelming problems? Out of the cries of our hearts came an answer! It was simple “Take a step, make a difference!” This 30 Day Prayer Guide is our “First Step! We are asking you to take this first step with us! Together we CAN make a difference in the lives of others who are living in complete hopelessness!

http://www.stepsofjustice.org/the-calendar/ - really recommend you get this - it's free but the people doing it are missionaries so maybe you could give more to bless their work.
Either way, get it and use in - in small groups, church, with friends, family, schools and make a difference to injustice, one step at a time...