Gardening Plan for Preschoolers in Oz?

We are planning a garden, mainly a veggie patch, for our preschool. It is Autumn here and we are looking for a planting program/plan to cover the next few months through to December (ie Winter/Spring/early-Summer). There is then a long summer break so anything left would have to fend for itself with minimal water. Our main concern is to plant things that the children are excited by. We are also considering whether raised garden beds would be a good idea (as well as a small veggie patch and a "digging" patch).