Great idea about the open house. Who's your targeted market? What income bracket do they fall in. Are you in a community area. WHy I ask is if there is a community newsletter publsihed, I would write a small article on a issue related to day care. Such as "How to select the Right Day Care for You." Then, place a classified ad in the newsletter as well. People reading your article will feel that you are an expert in your business. At the end of the article place contact information for parents to get in contact with you. Abother place you can visit is http://www.yourmarketingspecialist.highpowersites.com (this address will change in 2 days to http://www.yourmarketingspecialist.net.
I hope this helped.