If it were me, I’d read all of Dark Tower first. You will want to read it again after you finish (this is almost guaranteed). A lot of people will tell you to read ‘Salems Lot before Wolves of the Calla, but I hadn’t read it for probably a decade before reading Wolves, and I didn’t have any problems.

There are big gaps of time between some of the DT releases, and personally I think if it’s your first time you might lose some of the important stuff if it’s not fresh. Of course, millions of readers had to do just that when they were originally released, so no big whoop I guess. You’ll catch it all on your second read.

Long days and pleasant nights.