The official AMBER tutorials are located in the ambermd.org website located here.

This is an (ever growing) list of learning examples that not only focuses on CPPTRAJ but otherwise are related with molecular dynamics simulations.

Tutorials that involve building a structure, running a simulation and performing the analysis.
Analysis of a nucleic acid simulation.
Introduction to Principal Component Analysis
Tutorials related with visualization and representation of structures.
Making a movie from an AMBER trajectory using VMD