My kids have been helping me start seeds inside. We have flowers, herbs and vegetables. They love to fill the pots with dirt and planting the tiny seeds. It is very interesting for the kids to compare the different seeds. Some are huge and others tiny. My six year old liked the ones that were "spikey and looked like germs."
It has been been a great learning experience watching the plants sprout. Each plant's sprout is so different. My boys love to water them. We've found it helpful (and fun) to mist the seeds. They can spray as long as they want without overwatering the little sprouts.
In a few weeks we will take the plants outside and plant them in our garden. Imagine all the fun we'll have digging holes for all those plants!