Information here: http://the.earth.li/~sgtatham/putty/0.55/htmldoc/Chapter8.html

Quote: Original post by Anonymous Poster
One more thing... DO NOT use passwords that are present in a dictionary as passwords for ssh accounts accessible from the internet. Not even with some numbers like 123 attached to them. You'll thank me later for that too.

Question: Are there certain accounts I can give ssh permisison to and others I can deny? Can I deny root, for example, and only allow 1 specific user account access via ssh?

man ssh
Specifically, look in /etc/ssh/ssh_config.