The ability to characterize a variety of nanoscale properties together with topography in any environment is key to the power and broad applicability of atomic force microscopy. While accessing properties in the realm of electrical, thermal, chemical, and electrochemical measurements is also common, the atomic force microscope (AFM) is best known for its unique ability to measure mechanical properties. This application note provides an overview of nanomechanical characterization with an AFM, focusing on measurements of the most broadly applicable mechanical properties on the nanoscale: elastic modulus, viscoelastic properties, friction, and adhesion. The measurements described go beyond general mechanical contrast to provide semiquantitative and quantitative information about individual mechanical properties. Readers can expect to gain a framework for categorizing and understanding the various mechanical AFM modes.Descriptions of each mechanical property category, accessible for even the AFM novice, are given and examples from each property category, showcasing real samples and data, are presented.