This Master thesis is about researching critical online reading skills among high school students aged 15-19 and best practises used in social studies class to teach digital media literacy. As the world has become more and more digitalized, it has become evident throughout the Western world that the ability to navigate the information online is an important skill to possess. All over EU and USA/Canada the government reforms have brought digital literacy classes to the curriculum, often with hesitations on how to proceed the best. The paper will first present some of the previous research done on critical reading and digital media literacy classes in schools and try to pinpoint the most important factors and best practises already existing. Then we will explore the design process behind the final prototype – a tool for teachers for better media literacy education in social studies classes.