Stoners...How do I select grade in a granite staircase?

Ahem…I meant Masons…I am wanting to build a stone staircase on the side of my house in, I want it to wrap up around a 15 foot height over approx 35 feet. Semi-circular wrap.

What types of Jointing should I use, and what kinds of irrigation would fit the size of the job? Obviously I am about to get peppered with snow, so I’ll be doing this in the spring…I am just going to cut the granite in my garage this winter and I need to know some of the finer points of choosing grade, and what kind of joints I’ll need. Thanks ~Phil