Answer: You are probably in zone 7 but depending on your microclimate you may be in zone 6. By this I mean an open windy spot will be colder than a sheltered protected spot; in fact, since good gardening is often the result of trial and error this kind of observation may be your hardest question. You are starting out on a wonderful experience!
There are any number of plants that should do well for you, especially with both eastern and western exposures to work with. Generally speaking, plants for an eastern exposure (in the sun only in the morning) prefer cooler part shade to sun and plants for a western exposure (in the sun in the afternoon - usually after one or two o'clock when it is hottest in the summer) prefer hotter and drier conditions in full sun to part shade. To begin to select plants, look for those happy in zones 3 through 8 and then select based on light and moisture and soil conditions.
You might also find it really helpful to consult some good basic gardening reference books such as Gardening For Dummies by Michael MacCaskey ISBN 1-56884-644-4, and to talk to any good gardeners in your neighborhood -- local, experienced gardeners are usually your best reference when beginning a garden.
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