http://www.cineversity.com/vidplaylist/face_rig_tutorial/face_rig_tutorial_-_introduction

In this series, Can Erduman shows how to create a Face Rig using the new features of Cinema 4D R23 for his short I'Artista.

In this introduction, you will learn about the contents of this course. The face rig comes with great features and functions. This can be difficult and overwhelming at sometimes. We will first talk about the general differences between blendshape based rigs and joint based rigs. Then we jump right into the rig creation, adjustment and weight paint phases. With the rig completed, we will attach it to a body and learn how to use the pose library to animate. For the animation, I will give you some nice tips, too.

Here are additional informations, you should watch for the course:

Weighting:
General workflows:
Siggraph 2015 Rewind - Bret Bays: Weighting Workflows for Cinema 4D Character Animation

Weighting for Joint based facial rigs:
Toon Rig Series: Weighting the Face