This text is aimed at people who have some familiarity with high-resolution nmr and who wish to deepen their understanding of how nmr experiments actually work. This revised and updated edition takes the same approach as the highly-acclaimed first edition. The text concentrates on the description of commonly-used experiments and explains in detail the theory behind how such experiments work. The quantum mechanical tools needed to analyse pulse sequences are introduced set by step, but the approach is relatively informal with the emphasis on obtaining a good understanding of how the experiments actually work. What this book is about and who should read it. Setting the scene. Energy levels and nmr spectra. The vector model. Fourier transformation and data processing. The quantum mechanics of one spin. Product operators. Two-dimensional nmr. Relaxation and the noe. Advanced topics in two-dimensional nmr. Coherence selection: phase cycling and field gradient pulses. Equivalent spins and spin system analysis. How the spectrometer works.