This webpage has some great ideas for interacting with clouds this week; I think I'll have my son place pictures of clouds in different categories (there's a cloud altitude calculator for students who are really into this).
As an art project, we're going to draw the different types of clouds in white crayon on white paper--then paint over it with blue paint, which the crayon will repel, leaving the cloud types on a blue sky! (...We'll see if it works that well outside of my brain.)
For fun, here are some beautiful photos of clouds from National Geographic; your children might try their hand at identifying a few of the types.
For older students, this cloud diagram and information may be helpful with our new terms this week.