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The nucleon has been used as a laboratory to investigate its own spinstructure and Quantum Chromodynamics. New experimental data on nucleon spinstructure at low to intermediate momentum transfers combined with existing highmomentum transfer data offer a comprehensive picture of the transition regionfrom the {\it confinement} regime of the theory to its {\it asymptotic freedom}regime. Insight for some aspects of the theory is gained by exploring lowermoments of spin structure functions and their corresponding sum rules (i.e. theGerasimov-Drell-Hearn, Bjorken and Burkhardt-Cottingham). These moments areexpressed in terms of an operator product expansion using quark and gluondegrees of freedom at moderately large momentum transfers. The sum rules areverified to a good accuracy assuming that no singular behavior of the structurefunctions is present at very high excitation energies. The higher twistcontributions have been examined through the moments evolution as the momentsevolution as the momentum transfer varies from higher to lower values.Furthermore, QCD-inspired low-energy effective theories, which explicitlyinclude chiral symmetry breaking, are tested at low momentum transfers. Thevalidity of these theories is further examined as the momentum transferincreases to moderate values. It is found that chiral perturbation calculationsagree reasonably well with the first moment of the spin structure function$g_1$ at momentum transfer of 0.1 GeV$^2$ but fail to reproduce the neutrondata in the case of the generalized polarizability $\delta_{LT}$.Comment: 21 pages, 4 figures, review for Modern Physics Letters A. Minor  modifications in text and improved quality for one figure. Corrected mistakes  in section

SUM RULES AND MOMENTS OF THE NUCLEON SPIN STRUCTURE FUNCTIONS