The League of American Bicyclists is the offical site for National Bike Month. They say to:
Check the events section often to see what bike month and bike to work week events are going on in your community. If you would like to submit your event information to be posted on this site, email it to firstname.lastname@example.org. Please make sure you write, "Bike Month Event" in the subject line of the email.
Make sure you encourage others to bring their helmet on the bike to work!