Book excerpt: Electron magnetic resonance spectroscopy is undergoing something akin to a renaissance that is attributable to advances in microwave circuitry and signal processing software. EPR: Instrumental Methods is a textbook that brings the reader up to date on these advances and their role in providing better experimental techniques for biological magnetic resonance. Chapters in this book guide the reader from basic principles of spectrometer design through the advanced methods that are providing new vistas in disciplines such as oximetry, imaging, and structural biology. Key Features: Spectrometer design, particularly at low frequencies (below X-band), Design of spectrometer components unique to ENDOR and ESEEM, Optimization of EMR spectrometer sensitivity spanning many octaves, Algorithmic approach to spectral parameterization, Application of Fourier Methods to polymer conformation, oximetry, and imaging.