As a fellow constant reader, do it. The Dark Tower series ties everything together, all his works revolve around this one in a way. It can seem daunting, but trust me, those pages can't turn fast enough as you're reading them.

I caution the series to newbie King readers for the very same reason. The series is long, and they won't understand all the references and tie-ins. You will though, and you'll enjoy it (or I hope so, I've never met a fan who doesn't like them [except for the ending, but what King book doesn't have a contentious ending?]).