A number of standards have explicit or implicit obligations for assurance of risk-based properties. However, they often contain little guidance on how this should be demonstrated, for example, how to present a case with clarity, or how to determine whether it is sufficiently robust for its purpose. This guidance addresses this shortfall in guidance through an introduction to assurance cases and relevant supporting information. The underpinning principles of assurance can be applied to any property. The focus of this guidance is on risk-related properties, for example: safety; security; availability.