David Good I actually like starting with this series. Definitely read it before "The Stand" as it will give you a completely unique understanding of one of the main characters in "The Stand."
Nora Watson Cam has it right, they're more like fun treats for people who have read his other books, rather than important plot connections.
Cam Schitter There are characters and objects referenced in these books from Kings other books. But if you haven't read his other books that will not spoil anything. I was new to king when I picked up the gunslinger and it really got me reading his books. I catch myself smiling when I'm reading his other books and catch what to me seems like a dark tower reference, when really, the dark tower just took from kings other worlds. They are kind of like "easter eggs"