Here is some general info for USDA zone 7b to help you get started.
|Average Date of Last Frost (spring)||April 15|
|Average Date of First Frost (fall)||October 15|
|Lowest Expected Low||5°F|
|Highest Expected Low||10°F|
This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.
Below is a list of planting guides for Zone 7b.