Many Social action groups are provided in particular dioceses/cities/states - This section provides resources that are location-independant. Please search for catholic social action groups in your area - because there are many good Catholics doing amazing things!
Unites States Conference of Catholic Bishops Website - A wealth of information, from daily mass readings, to access to the catechism, to news, etc. Nice resource
Catholics who Care (Facebook Group) - Dedicated to performing small actions to end the problems in today's church, in the pursuit of personal holiness.
WINE - Women In the New Evangelization - Empowering women to work within their God-given gifts as women to nurture, heal and build up the body of Christ.