Cycling presents unique challenges at lower temperatures the worst of which may be (parodoxically) avoiding overheating.  Actually overheating one's torso. 

Most garmets made to insulate against standing around tend to make us overheated when we are exerting ourselves.  So when cycling in the 40s and 50s, it's best to use layers that you can strip off and pack easily.  Some of the best pieces to your wardrobe may be knee warmers and arm warmers which augment your winter cycling kit and are pack for changing weather conditions.

The parts that really suffer in the cold are feet.  They are particularly exposed and you're typical summer cycling shoe is intentionally vented.  In addition the metal cleats for pedal retention act as heat sinks.  A cheap remedy for this are wool socks which are superior to cotton and polyester in the winter in every way.  Second are neoprene overshoes specifically for cycling which adds an extra layer of insulation all the way around the foot.

The other type of shoes to consider are the ones that go on your bike ... tires.  The trails have been dry most of the summer and this has led to condition optimal for low profile treads.  Things have changed.  Now big, tall, widely spaced nobs that will grip through the leaf cover will help you the most.  These are the same type of tires that will help you most in the snow (if your adventurous).  My favorite are the Continental Mountain Kings, but there are plenty of treads in this category.

Just remember that you may need to experiment and you will probably have to start your ride cold in order to avoid stopping and stripping off layers.  So get out there and get some good riding in.  Check the articles section for more on cold weather cycling.