I am just about through Songs of Susannah...
The part about the "meeting of the writer" was VERY interesting.
Crazy shit - it's too bad I'm not a big fan of King, because all of the connections across almost every book he ever wrote are very compelling.
You can reference this site for all extraneous information - there's a lot more you miss reading these than you catch if you're not obsessive about his work (like me).
http://www.thedarktower.net/wiki/Main/HomePage