In recent years, advancements in single-biomolecule probing techniques have provided critical information on and greater insight into the nature of biomolecules. Of significance is the application of single-molecule fluorescence resonance energy transfer (smFRET) to probe isolated events and changes at the nanometer scales. In particular, the study of helicases using smFRET has supplied much information regarding the nature and dynamics of these enzymes and provided a toolbox for further investigations. In this chapter we provide a general guide for the construction and execution of single-molecule FRET assays for the study of helicase properties and functionalities.