The term is elusive and much confusion and mission drift has been caused by what is sometimes a less than biblical idea of what justice is. These resources help to keep the gospel central and discuss how Christians can live like Christians in their neighborhoods.
9Marks Interview: What is the Mission of the Church?
This is a good interview to listen to as Kevin DeYoung and Greg Gilbert discuss their book of the same title (http://www.amazon.com/What-Is-Mission-Church-Commission/dp/1433526905) Mark Dever.
DA Carson, David Platt, Michael Horton, John Piper and many more are also great guys to look to for helpful, exegetical answers.