You guys and gals probably already have your favorites. If you
Google /cloud photos/ that alone brings up a dozen great sites..

Gordo's Cloud Gallery is a good one.

http://www.capetownskies.com/clouds.htm

Here's another little favorite site of mine - part of what I do
with my life. You are all invited anytime you are in the area.
http://www.cedar-astronomers.org

We are nearing completion on the Eastern Iowa Observatory
& Learning Center. I'm a general fix-it-all and spectroscopy
junkie.

Best to all -
Jerry