In the Fall, plants slow down and get ready for dormancy.
It's time to remove those tired looking summer annuals and replace them with Mums and Pansies. The pansies will flush out and bloom again in the spring.
It's best to remove leaves from the lawn promptly, as leaving them may cause damage to your lawn. Compost them if possible to use as fertilizer in the spring.
You may notice some evergreens shedding the inner leaves/needles (see picture below). For example, white pines will show yellow needles along the stem, but this is perfectly normal. Arborvitaes will, also, display similar behavior with the browning on the interior of the plant.
Continue watering evergreen plants. This is necessary until the ground freezes, usually around January. Once the other plants have lost their leaves, no watering is necessary.
Be sure to mulch plants well for protection in the cold weather.
Deer damage is most often the result of males rubbing their antlers against trees causing significant damage. This is done to remove the velvet from the antlers. Once the velvet is removed, they may continue to rub in order to polish the antlers. Deer, also, rub to attract females during the rutting season. This can result in broken branches and torn tree bark.
The best deterrent to this damage is to make the trunks inaccessible. There are several options to protect them. The trunks should be protected, not wrapped. Wrapping can cause other problems. Using tree stakes or other types of stakes, you can create a physical barrier to the trunk. Wrap the stakes with chicken wire, hardware cloth or plastic netting (see picture below).
There are many resources available on how to protect trees from deer. As with most anything, finding the method that works best for you is the answer.