How fun, and how exciting! A combination of useful and fun with a variety of ways to promote it. Looks like you have 2 different targets, individuals and educators. It's easier to go where the kids are, and that's in schools. I would make up a flier thing and blanket the whole county - er, I mean I would mail them to individual teachers, PTO members and after-school program managers. Daycares, too.
There are also companies like this http://www.reallygoodstuff.com/
that supply educators and others with educational stuffola. Do some research and see if you can work out some wholesale deals if you're at a point you can do that.
I would do some research to find all the parenting/teaching blogs, magazines and so on out there (including trade magazines for teachers), then write and send out press releases. Put it this way: It's cheaper than advertising, and if you don't do it, you won't get a bite from anyone out there who might be interested in you. If you do it, you might get lucky and someone will think you're the coolest thing ever. Which do you prefer? You can expect to get calls from folks wanting you to advertise, but don't get sucked in.
If you want to reach individuals, well, that's more difficult, but if you know anyone at all, they should have a supply of your business cards in their bags or wallets, handing them out to people they know. Try to work out deals with local kids' stores. Local community centers have birthday parties; you could sell your crates to them as a birthday activity.
You could set up classes at churches, community centers, or schools with the crate cost paid as part of class fees. Make it on the weekends so more parents can join in and you can sell them on subscriptions. You want to sell your product, not become a daycare. If you make it a parent/child class it will be better for sales.