Start small. Your garden will become a classroom from which there is no graduation. A bed that is 3- 4' wide by 16-20' long will grow an astonishing amount of produce. But, doubling the planting area won't grow double the food if you aren't able to manage it effectively. Plant the first bed this year, while preparing a second bed for next year using any of the raised bed techniques. By next year, you'll have a much better feel for what you are doing.