Traveling to Germany to WWOOF from July to October. Was wondering how simple it is to get a cheap 3 month German phone plan?

Traveling to Germany to WWOOF from July to October. Was wondering how simple it is to get a cheap 3 month German phone plan. Also I am curious about whether the plan (if there is a good one) would work throughout any other countries in europe (I am probably going to the netherlands, france, spain, and switzerland). Verizon is trying to sell me on using their international data rates and getting a global phone but I feel like there may be a better and cheaper way.

Any advice on having a phone while traveling would be helpful. I am from the United States and will not be trying to call people here while I am in Europe. I will use skype and free internet tools to do that form of communication.

Thanks A Lot!!