There's a lot to know in planting a garden, whether it is your own, a community garden or a school garden. Below are links to several fact sheets provided by UNH Cooperative Extension that cover some of the topics of interest to new or continuing gardeners. You may want to print them out and provide them in a binder for your community garden participants.
Getting Started:
Preparing a Vegetable Garden Site
Soil Testing Home Grounds and Garden Submission Form
When to Plant Your Vegetable Garden
Growing Vegetables in Containers
Composting, Fertilizing, Mulching
Using Animal Manures and Manure-Based Composts
Organic and Natural Fertilizers
Growing and Caring for Specific Crops
Dealing with Insects and Disease
Preventing Common Garden Diseases
Plant Diseases and Diagnostics Submission Form
Insect Identification Services Submission Form
Where to Find More Help