A large amount of personal and very incriminating data is currently stored on websites, apps and social media platforms. Users often update these data daily, and this data is open source. This information can become evidence for citizens, governments, and businesses to use in solving real financial, employment, and crime problems with the help of a professional information collector. To respond to this new situation, it is important to have well-trained staff. The fact that many authorities and companies work with very sensitive data makes it necessary to train their employees in Open Source Intelligence (OSINT). Motivated by these facts, a practical training concept is developed that enables the creation of practical exercises. The focus is on the practical implementation of OSINT tools and methods. In the new course, participants learn legitimate and effective ways to find, collect, and analyze this data from the Internet. We have developed an introductory course for a Master level program in Open Source Intelligence (OSINT). Students learn up-to-date, hands-on skills, techniques, and tools that law enforcement, private detectives, cyber attackers, and defenders use to search the vast amount of information on the Internet, analyze the results, and build on interesting data to find other areas for investigation. Our goal is to provide the OSINT knowledge base for students to succeed in their field, whether they are cyber defenders, threat intelligence analysts, private detectives, insurance inspectors, intelligence analysts, law enforcement, or just someone curious about OSINT. Throughout the course that consists of 11 exercises, students will participate in numerous hands-on exercises using the OSINT tools and techniques that form the basis for collecting free data from the Internet.