Introducing the new CNA Study Guide 2020-2021. How is this guide different from others? This guide has 4 full-length practice tests, answers along with explanations and test preparation strategies. About Newstone Test Prep Newstone Test Prep is a major publisher of study guides for students in various countries including the US, Canada and UK. The study guides are prepared by specialized teams who are very knowledgeable about the exams. The authors and editors pool resources together to create authentic test questions that are very useful for students. Because practice exams are created in the same format as the real exams, students are able to take mock exams before taking the real exams.