Excellent site: National Priorities Project
http://nationalpriorities.org/en/about/mission/
National Priorities Project (NPP) makes our complex federal budget transparent and accessible so people can exercise their right and responsibility to oversee and influence how their tax dollars are spent.
NPP envisions and works for an effective and accountable federal government that promotes our general welfare. We believe the U.S. federal budget will reflect the values and priorities of the majority of Americans when all people have the opportunity and ability to participate in shaping the nation's budget.
Most of us in the United States dont know where or how our federal tax dollars are spent. Many factors have distanced us from the personal and societal impact of federal spending, and barriers have prevented us from having influence over the creation and oversight of our national budget.
Together National Priorities Project, Peace Action and a terrific group of colleagues, have assembled all the materials you need to enter the current national debate about Pentagon spending, while building the capacity of colleagues and allies to join in as well.
http://costofwar.com/publications/2013/move-money/