Question

Chard, broccoli and swiss chard will likely be winter crops in your area. Best soil prep I have used (for > 30 years) is cover cropping with legumes (crimson clover, fava beans, etc depending on how late I get them in: favas will germinate any month of the year, even here on the rainy OR coast), making lots of compost with dairy manure and garden and kitchen leavings and keeping things well weeded. Sometimes I cover vacant beds with organic straw (~$5.00/bale) for the winter months. It would be useful for you to get your soil tested at your local Extension Office for nitrogen (N), phosphorus (P) and potassium (K) as well as pH (acidity/alkalinity level), as different crops require different levels of each macronutrient. Organic rock powders (greensand for potassium, rock or soft colloidal phosphate and/or bone meal for phosphorus and blood meal for nitrogen are useful additions to your compost pile. Kelp meal and glacial rock dust are wonderful additions for micronutrients. A good book to get started with is "How to Grow Fruits and Vegetables by the Organic Method" published by Rodale Press. I don't know if it is still in print, but you could likely find a copy online at a used book site. It's the one I started my lifelong gardening journey with back in the early 70's. Hope this helps.