The recent advances in instrumentation and methodology are thoroughly described so that their new capabilities may be applied to unsolved scientific problems. Bringing together contributions from professionals at the forefront of this rapidly developing area, it documents the most exciting breakthroughs to date. Discussions include new techniques of Fourier transform and two-dimensional electron spin resonance, and advances in electron spin-echo spectroscopy. New methods that show promise for the future are explored, such as transient electron spin resonance with continuous wave detection, and electron spin-resonance imaging.