Becoming a spotter is easy! Simply attend a storm traning class taught by the National Weather Service, hosted by various communities throughout the Multi-County Skywarn area.

For questions on becoming a spotter, check out the Chicago National Weather Service's Spotter FAQ.

Some online downloads are available to learn a little bit about severe weather and spotting techniquies..
Basic Weather Spotting Field Guide (.pdf)
Advanced Weather Spotting Field Guide (.pdf)

Or if you would rather see an online version of the NOAA Severe Storm Spotters guide ..
Check out the University of Illinois' version

Want to know the history and purpose of storm spotting? You should read this paper, " Storm Spotting and Public Awareness Since the First Tornado Forecasts of 1948", written by Charles Doswell III, Alan Moller, and Harold Brooks.