How to make the most of your soil type discusses how to identify and amend six garden soil types.
Building soil - directions, with photos, yon how to build a lasagna (sheet composting) garden.
The Canadian Organic Grower's Organic Field Crop Handbook discusses The Soil Ecosystem.
COG article -Weeds: Don't Shoot the Messenger - what weeds tell you about the condition of your soil. If you don't know what weeds you have, Weeds Canada has photos + the common and latin names for weeds.
Penn State extension has many information sheets on soil management.
An online soil biology primer by Dr. Elaine Ingham.
Soil Beneficial Bacteria and Their Role In Plant Growth Promotion - an academic review