First off it might be good to read and understand this:
http://www.state.me.us/ifw/wildlife/species/deer/feeding_deer.htm

If they winter on your property, or property you have access to and permmision to mess with you can also check out this link (with an embedded link to preferance list of prefered winter foods) for some ideas:

http://www.dec.ny.gov/animals/7205.html