What is the cheapest and best way to prevent water from entering a crawl space? What preventative measures can I take? The Atlanta rains did me in, but I was one of the lucky ones.

It depends on how the water is coming in, land drainage around foudation, down spouts not running away from home,

This week in atlanta a 10 foo dike perhaps

What is the cheapest and best way to prevent water from entering a crawl space?

A french drain, (see image) comes to mind. Click on;french drains how to - Google Search (http://www.google.com/search?sourceid=navclient&aq=t&ie=UTF-8&rls=GGLJ,GGLJ:2006-43,GGLJ:en&q=french+drains+how+to)
To learn more. Good luck, Tom