I was unable to find any resource listing ALL icons for Solution Explorer and/or Navigator explaining their meanings. I mean, for somebody new to that, seeing a square, a question mark, or a no entry sign, next to a file, is pretty obscure.
Any help much appreciated
If you mean the "Source Control Item Status" icons that appear next to files in the tree view.
See http://msdn.microsoft.com/en-us/library/ms181372(v=vs.80).aspx