Here are some suggestions for getting your garden ready for next year:
Clean up the garden. Cut back soft plants, annuals, perennials, and groundcovers close to ground. Leave taller, stiffer plants standing.
Use an organic mulch in shrub and perennial beds to cover plants. Use your leaves or compost.
Water your plants generously. The leaves are falling, but the feeder roots are still active
Apply a winter fertilizer to your lawn. It should be a low nitrogen "Winter" blend, not your regular summer fertilizer. High potassium rating stimulates strong roots.
Here are some things NOT to do
Don't prune plants in the fall. It creates too much stress, and creates cuts for bugs to enter.
Don't cover the roses too early. Let them prepare for winter on their own and cover well once the ground is frozen.
Don't till the soil in the fall. Let surface plant material hold the soil together to protect from wind and water erosion.