This animated visualization of precession, eccentricity, and obliquity is simple and straightforward and provides text explanations. It is a good starting place to show Milankovitch cycles.
This short video, adapted from NOVA, explains how Earth's position relative to the Sun might be responsible for the dramatic shift in the climate of what is now the Saharan nation of Djibouti.
These animations depict the three major Milankovitch Cycles that impact global climate, visually demonstrating the definitions of eccentricity, obliquity, and precession, and their ranges of variation and timing on Earth.
An applet about the Milankovitch cycle that relates temperature over the last 400,000 years to changes in the eccentricity, precession, and orbital tilt of Earth's orbit.
This figure shows the various astronomic cycles that influence long-term global climate cycles (Milankovitch cycles), plotted on the same time scale for easy comparison.