How does zinn describe the american revolution? 2. in what way was colonial military service unfair to poor common people? 3. george washington's response to soldiers who rebelled. 4. historian charles beard?

You could say Howard Zinn is a Social Historian. He looks at events in history and the social impact they have on the people and time. Zinn saw the Revolution as an avoidable war. He doesn't see war as a necessity to gaining what one wants. 
The common poor soldier didn't benefit near what the richer classes did. According to Zinn, people were promised things that they never received. Others were bullied into joining the cause. Washington was brutal to those soldiers that deserted. We have a very idealized view of him. Zinn points out that the common soldier had very little while the officers like Washington were eating large meals, constantly had access to fine clothes, and never lacked for shelter. The common soldier never knew if he would eat during the early parts of the war. Everything surrounding Valley Forge is true. Many men died due to lack of food and exposure to the elements. 

Charles Beard looked more at the economics of the situation. He saw all the decisions made based on the economic impact it would have on those making the decisions (wealthy and elite). Beard was part of the Progressive interpretation of history; basically they analyzed the actions and decisions around the idea of class and money. Those in power took actions to maintain their place in power without the common man realizing it.