Garry E. Lewis has revealed the First Arnold Shader set in his new rendering series. The set features 12 base Arnold shaders and a testing base Maya file with a ready lighting setup. 12 shaders will be installed automatically to make things easier.
You just need to download the installer and run it in order to use the pack. The shaders are only for Maya 2017. The artists has also included a Maya scene file with lighting set up for you to play with shaders. He is also working on some tutorial videos, which should appear here.
There are two separate files for Windows and Mac users.