There are a few simple measures that you can take with your hives to ensure that you're giving them a good start going into the winter. Here in central PA, our biggest worries going into winter are starvation and condensation. Check that top super and make sure that it is really really heavy. If it's light, you will definitely want to feed a sugar syrup.
For the fall, the ratio of sugar to water should be 2:1. The bees may not cap sugar syrup once they bring it into the hive. As weather starts to get cool, try to get the sugar syrup as close to the cluster as you can. One way to do this is to remove your inner cover, put the syrup in a quail feeder, and place the feeder directly on top of your frames. Encase the quail feeder in an empty deep super to prevent robbing. If you don't have a quail feeder, there are certainly other options. A chicken feeder will work too, as long as you put gravel or sticks in the reservoir so that the bees don't drown.
Believe it or not, condensation is a far greater threat to your bees than are cold temperatures. Luckily, there's an easy way to combat condensation. Arrange your inner cover so that the front notch in in the upside-down "U" position. Then, put an empty deep super on top of the inner cover. The condensation should collect in the empty super. If it doesn't dissipate, any drops of water will fall down on top of the inner cover rather than on top of your cluster.
Got any other ideas for winter prep? Please feel free to comment!