Don't worry too much about the USDA planting zones - that's primarily relevant for perennial plants, where you have to consider whether they'll be able to survive the winter.
For vegetables and herbs, just look at their growing characteristics (e.g. whether to start indoors or out, and when to sow/transplant relative to the last frost date). That info is detailed on the website and in the Square Foot Gardening book; you can also extrapolate from the garden plan that I'm planning to use.