At a recent conference I found out that the World Meteorological Organisation (WMO) is going to move their official international cloud atlas (ICA) which used to be a hard bound book, to an online portal. ^
The website for this new portal is here:
http://wmo-cloudatlas.org/index.php/en/
Currently, the home page is for image submission only and I would suggest that you just check it occasionally to see if they have finally made the atlas available online or not (rather than try to submit photos as there are quite specific requirements for the subject and image)...
For the real Cloud enthusiast (or indeed aviation weather geek), the link on the header of the above WMO page (heading Links) allows you to download both the older volumes (scanned paper copies) of the ICA (vol 1 and 2). Vol 1 is a text document that describes the various clouds and meteors in the sky in words, with vol 2 being pictures of those phenomenon.
Trust this will be of use and provide some hour(s) of learning/pleasure to those interested in this thread and topic during your travels. @:-)