START A GARDEN edited by Mary Yee (Chronicle Books: $9.95; 111 pp., illustrated, paperback original). The arrival of spring inspires even urban residents to get back to the soil, and this colorful installment in Chronicle's "Do It!" series offers simple instructions for planting flowers, herbs and vegetables. Yee sensibly sticks to easy-to-grow plants: People who want to transform the back yard into a mini-Xanadu can consult more technical volumes. The small format makes the book easy to slip into a pocket during a gardening session or a trip to a the nursery.