Keep each year's plan in a three ring binder for easy cross-checking of varieties, rotation, etc. Spend a cozy evening in front of the fire going through seed catalogs to decide what you are doing to plant in this year's garden. As you peruse seed catalogs, choose disease-resistant varieties. They not only make gardening easier, they reduce expenses and environmental pollution from pesticides. Don't wait until late in the winter to order seed.
Many varieties sell out early.
It's also time to recycle your holiday decoration. Greenery used in ornaments can be used again in the garden. Wreathes and branches stripped from Christmas trees make excellent mulch for protecting newly planted ornamentals. Remove the material in the spring and compost it. If you are spreading the ashes from your wood-burning stove or fireplace in your garden, be aware that over time, you are raising the pH of your soil.