Here's some inspiration and how-to's from the Kitchn:
How to Start a Green Roof Garden
How to Start a Community Garden
How to Make a One-Pot Herb Garden
Planning a Window Box
Victory Garden Project
Our Small San Francisco Container Garden
Book Review: Designing the New Kitchen Garden
And a few more resources from around the web:
The Old Farmer's Almanac - Handy for predicting when the last frost in your area will be
The National Gardening Association - A good all-around resource for how-to's, pest control info, and buying guides.
Starting Seeds Indoors from Garden Guides
How to Construct a Raised Planting Bed from WikiHow
Vegetable Gardening in Containers from AgriLife/Texas A&M
What are your garden plans this year?
Related: How Far Does Your Food Travel?