This tutorial offers two slideshows: one for colons and one for dashes. They each state the purpose of the mark and tell when they are used along with examples.

This slideshow lesson focuses on appositives by defining them, showing they can have modifiers, explaining when to use/not use commas, and how to use dashes, parenthesis, and colons with appositives.

A map from 1916 of Asia, showing physical features, general elevations, and mean isotherms for January and July. This map uses color-contours to show land elevations ranging from below sea level around the Caspian Sea to over 12000 feet,...