If you are new to gardening and growing your own food, don't despair!
First things first, you need to know what can grow where you live.
Your planting zone will be your guide to assure that the plants you select will flourish year after year. The planting zone is particularly helpful if you select plants that are perennials, bushes, or trees. Perennials are plants that will grow for more than two years and typically dies back in hard frosts.
Check out the USDA plant hardiness map to find your "zone".
We are zone 5b. Which means the weather can get to below -15 degrees Fahrenheit and our growing season come to halt with the arrival of winter.
You need to know what zone you are in to know if the plants and seeds you select to grow will do well where you live. For example oranges can't grown in Wisconsin because our growing season is too short, so I shouldn't order an orange tree on-line.
Zones on Seed Packets:
The zones on the back of seed packets guide you to know when to bring your delicate seedling outside that you have cared for over the last weeks. You want the seedling to grow outside as it will do better than inside your home.
According the back of the pictured packet of tomatoes we are living in the zone 4. In zone 4 it is May to June for this seed packet.
With this knowledge you can get the most out of the plants where you live.