Read-Only file system

[steveb99]

I appear to have hosed myself and having trouble finding out what I do 
and how to fix it.  It appears that many of my file-systems are now 
saying they are read-only and I can't do anything with them, even when I 
login as root. 
I'm still learning so not a production mess. Can someone point to me how 
a file system can become Read-Only, the file permissions are fine.    
Also can this be repaired if so what should I be reading to learn to do 
that.

TIA,
Steve B.