In a day when we are looking up towards going to the Moon, a web site that has a lot of material about amature rocketry and links to much more is http://www.arocketry.net/index.html

One of the pages that shows a lot of material written and available on line is
NASA SPACE VEHICLE DESIGN CRITERIA SP-8000

What Arocket List Members Are Doing

Have fun.
Larry Kellogg