The sections on 13C NMR and proton NMR are written so that they are entirely independent of each other. That means that you will find quite a lot of duplication in the "Background" pages for both techniques.
If you have a choice, start with 13C NMR. The spectra are a lot easier to interpret!
Background to proton NMR
An explanation of how a proton (1H) NMR spectrum arises, and the meaning of the term "chemical shift".
Low resolution NMR spectra
How a low resolution NMR spectrum is used to identify where the hydrogen atoms in a molecule are. Read this before you go on to high resolution spectra.
How to find the ratio of the numbers of differently placed hydrogen atoms from an integrator trace.