When I started out (4yrs ago) ALL my families came from Kijiji. I had a very detailed write up with a link to my even more detailed website. I had lots of pictured (I used non-descript close up photos of my friends children playing).

My ad was very carefully written to not mislead and not give false info but to also not say I was not yet up and running. The last thing a new parent looks for is "brand new daycare, i have all spots available" The key is to win them over in your writing, get them out to the house to fall in love with you then you break the news you have no kids yet. I had plenty of child care and teaching experience and a child of my own so it wasn't that concerning to them when they found out, but only because they read my website and met me first!