Building Fertile Soil  
   Guide to creating and maintaining good quality soil.
   http://zzyx.ucsc.edu/casfs/gardenideas/soilfert.html

Soil  
   Gardening and in particular, soil information from the Oregon State University.
   http://eesc.orst.edu/agcomwebfile/garden/soil/

Soil and Fertilizers  
   Publications about fertilizing a number of different plants, from the North Dakota State University.
   http://ndsuext.nodak.edu/extpubs/soilfert.htm

Soil Management  
   A number of publications (in PDF format) dealing with topics about soil.
   http://www.uwex.edu/ces/pubs/soilcat.html

Improving Soil  
   Instructions for improving soil. Includes soil components, soil testing and soil amendments.
   http://www.rodsgarden.50megs.com/improvingsoil.htm

Better Homes and Gardens: Soil, Water & Fertilizers  
   Includes articles on making potting mixes, proper watering techniques, nutrient needs, and mulching.
   http://www.bhg.com/bhg/category.jhtml?catref=C401

Understanding the Soil Processes  
   Information about soil composition and the biological processes occurring within the soil.
   http://www.petrik.com/PUBLIC/library/ups.html

Foster's Sustainable Organic Soil Program  
   Resources to learn the importance of using natural products to take care of the soil ecosystem.
   http://www.fosterssos.com

Iron Chlorosis  
   Explains iron chlorosis in trees and plants, and how to correct it.
   http://ohioline.osu.edu/hyg-fact/1000/1009.html

Lead Contamination In The Garden, HYG-1149-93  
   Ohio State University
   http://ohioline.osu.edu/hyg-fact/1000/1149.html

Micronutrient Disorders, HYG-1252-98  
   Ohio State University
   http://ohioline.osu.edu/hyg-fact/1000/1252.html

Physical Characteristics of Growing Mixes, HYG-1251-97  
   From Ohio State U.
   http://ohioline.osu.edu/hyg-fact/1000/1251.html

Soil Testing is an Excellent Investment for Garden Plants and Commercial Crops, HYG-1132-99  
   Ohio State University
   http://ohioline.osu.edu/hyg-fact/1000/1132.html

Guidelines for Choosing a Soil-Testing Laboratory, HYG-1133-99  
   Ohio State University
   http://ohioline.osu.edu/hyg-fact/1000/1133.html

Improving Soils For Vegetable Gardening, HYG-1602-92  
   Ohio State University
   http://ohioline.osu.edu/hyg-fact/1000/1602.html

Fertilizing Vegetable Garden Soils, HYG-1601-92  
   Ohio State University
   http://ohioline.osu.edu/hyg-fact/1000/1601.html

World of Soil  
   An introduction to understanding the basic components of soil.
   http://soil.hostweb.org.uk/

Building Great Soil  
   Information on testing and improving planting soil. Includes a section on raised beds.
   http://doityourself.com/garden/buildinggreatsoil.htm

Soil Resource Management  
   References about the fertility, compaction, testing and conservation of soil. Published by the University of Nebraska.
   http://ianrpubs.unl.edu/soil/

Vermiculite.com  
   One-page site giving suggestions on where to purchase vermiculite in the United States, along with some uses and properties of vermiculite.
   http://www.vermiculite.com

Improve Your Garden Soil  
   Covers a wide range of garden soil topics, including soil types, pH, nutrients, testing, composting and fertilizers.
   http://www.improve-your-garden-soil.com/