  In this, the first in a series of three papers concerning the SuperCOSMOS Sky
Survey (SSS), we give an introduction and user guide to the survey programme.
We briefly describe other wide-field surveys and compare with our own. We give
examples of the data, and make a comparison of the accuracies of the various
image parameters available with those from the other surveys providing similar
data; we show that the SSS database and interface offer advantages over these
surveys. Some science applications of the data are also described and some
limitations discussed. The series of three papers constitutes a comprehensive
description and user guide for the SSS.
