Oklahoma Garden Planting Guide
For those of you who are new to vegetable gardening, I've linked OSU's Garden Planting Guide. It is full of useful information, but you should apply some common sense and alter their recommendations as needed/if needed.
For example, even though they give fairly specific planting dates for most kinds of vegetables, you can't blindly plant "by the calendar" if the weather conditions are not appropriate for planting a given crop on a given date. When planting, you have to take into consideration the average soil temperature of your soil at planting depth, the air temperature and the forecast. If either the ground or air is not reliably warm enough, you'll need to wait and plant after they reach the right range.
Spacing also is highly variable. You may find you use different spacing for specific reasons--like, maybe you're growing either the Square Foot Gardening way and want to follow Mel's spacing recommendations or you're growing following John Jeavon's Biointensive method and want to use his recommended spacing and interplanting methods.
Still, it is a very useful guide. Just taylor the recommendations to suit your specific needs.
Here is a link that might be useful: Oklahoma Garden Planting Guide