The Kosciuszko Foundation's Teaching English in Poland Program runs a summer program in several locations across the country.  Both teachers and college students are needed.  Students don't need to meet any any special requirements to work as a teacher's assistant.  

Students' age groups are from 10 to 19 and you have a choice of your preferred age group.  ESL students had to pass a test to qualify for the summer camp so you don't need to know how to teach grammar, etc.  You basically have to converse with the students.  Classes are conducted in the morning and in the afternoon there are short day trips, sports, arts and crafts sessions, and various other activities.  Both teachers and teacher assistants receive free room and board.  

At the end of the ESL program all ESL teachers are granted a free week long tour around Poland, visiting major cities such as Krakow and Warsaw, the Baltic sea,  and the mountains.  Poland is a great starting point to continue exploring the rest of Europe for the rest of the summer.

To find out more about this ESL program you can watch a video on the Kosciuszko Foundation's Teaching English in Poland  http://kfblog.thekf.org/?cat=25