Experimental and theoretical investigations of NK absorption near edge structure (XANES) of organic compounds with different coordination, charge and bonding at the nitrogen atom, are reported. In order to explain general features of the spectra from thiourea, pyrrole, polypyrrole, tetraalkylammonium salts as well as from substituted benzalanilines, the spectral distribution of oscillator strengths for transitions from the N 1s level to excited discrete and continuum states have been calculated applying a quasiatomic model. The analysis of the theoretical and experimental spectra provides evidence of the central role of splitting of an intense N 1s^-12p resonance in N K XANES formation in all compounds under study. The influence of the electronic charge transfer, bond conjugation and localization on the energies and intensities of π* and σ* resonances, are discussed in detail. Intramolecular resonance effects are shown to dominate the N XANES features of the compounds.