Do not overdo the colors. Each color costs about 25 cents extra per shirt. A well designed three color shirt can be very effective. Consider using seconds. Use someone who knows what color separation and camera ready actually means, otherwise you might have to pay a middle man extra to perform this function.
Police Give the local police departments as much notice as possible.
12 months is a good idea. If you leave this to the last minute, you will pay. They will probably want detailed course maps showing every intersection and the times at which the lead, mid-pack and last runners pass through each intersection. You should provide this information. Your race cannot exist without the Police.