[ale] Looking for ssh key explanatory documentation

[David Corbin]

I understand, reasonably well, all the various keys involved in SSH. ?However, 
I've got a bunch of co-workers that I think would benefit from a clear 
explanation of them all, what goes where when and why.

Can anyone point me at a good (medium to high level) descriptionof this? ?I 
kind of envision there being something with some good 'pictures' that would 
really make it clear.

Thanks.