The Complete Amiga 500 User Guide by  Peter Hutchison (2003)

Introduction - Welcome to the Commodore Amiga A500, one of the most popular Amiga models of its time. It was affordable, easy to use and good software in particular games which Jay Minor, the creator of the Amiga, had designed it for.

Thsi 40 page article is a great getting start guide, especially if you are interested in Amiga OS 1.3 as that is the main focus, although 90% of the information carries through to Amiga OS 2.x and 3.x.