The Xians are gonna have a brain aneurism over this if it gets enough coverage. You need a parade to really get people's attention in the press. Sort of like a pride parade but for atheism. A bunch of godless heathens going down Main St. USA denying the existence of god.
That's not gonna get ugly fast.
You may know I am the President of the Procrastination Club of America. We believe we would like to assist you, but we need a little time to think about that; and then some additional time to organize any help we may want to provide. You mentioned March 23rd will be Atheist Day. March 23rd of what year?
I will wear my Agnostic.com T-shirt. I will not be seeking the company of other nonbelievers, as I am not part of any organised group, being one of the few nonbelievers in this part of the world. If anyone comments on the logo on my T-shirt, I will explain to them about this site, and who knows, I might discover that there are actually other agnostics or atheists around after all!
You could do a gathering at city hall or the county building and do an education program and open mic for people to share their beliefs. Personally, I like to share the good things atheist do or have done because I think a lot of folks believe only religious people can do good things.