This Field Guide introduces key topics in cybersecurity and shares resources to help students build their knowledge. The book is designed to move beyond the classroom and utilized as a professional resource throughout their career. I bring over 25 years of experience in cybersecurity and IT both in the private- and public-sector, to include publicly-traded cloud providers. Technical knowledge in systems and networks is critical in a cyber career. You must know the infrastructure to apply security planning and risk management effectively. I started on the foundational level on help desk as an Information Systems Technician (IT) in the US Navy. I worked at every level in technology from system administration all the way through to network management. Each role built on the last, giving me a deep, hands-on understanding of systems and networks, experience that became essential as I moved into cybersecurity. For example, the knowledge I gained from systems helped me when I tested aircraft and weapon systems, performed IT audits, implemented security controls in different environments (e.g. cloud and on-premises), determined the vulnerabilities that affected environment, and so forth. Although it is beneficial to understand the theories and principles of security, it will be your hands-on experience that apply these theories and principles to real-world environments that fix the gaps in security.