First, congratulations on seeing fall as a second spring. I suggest you add shade tolerant perennials such as Japanese anemone, asters, hardy cyclamen and sedum 'Autumn Joy' to your area if you have a lot of room. If your garden is small or if you are gardening in containers then winter pansies and ornamental kale and cabbage will add color. If you just want to add plants that will bloom all through the year not just in the fall then go ahead and plant anything you find at the local nursery into the garden now. The cooler weather is great for encouraging root growth and it will be easier to keep the soil moist in the fall around newly transplanted nursery stock. In partial shade flowering shrubs such as azaleas, rhododendrons and  camellias can be added in the fall for a beautiful spring display. Dig in and welcome to fall gardening. Keep growing, Marianne Binetti