Because this course is focused on principles that you can apply in any medium, I recommend that you do the assignments in the medium you are most comfortable with. You can work digitally or traditionally. If you are working in traditional media, I recommend graphite pencil over charcoal because it is simpler and cleaner.
Mechanical eraser (Tuff Stuff or BM2)
Sandpaper pad (optional)
Cheap sketching paper for quick assignments
White Canson Mi-Teintes paper (160g) for more involved assignments
Digital: Computer + Tablet
If you work digitally with a computer, the graphic tablet I recommend for most people is the Wacom Intuos M:
You can use any digital painting application and device you like. All digital painting demos in the course are done in Adobe Photoshop. If you're curious, you can find a fantastic free intro to drawing and digital painting at www.ctrlpaint.com.
Digital: iPad + Apple Pencil
If you have an iPad and an Apple Pencil, Procreate is one of the most popular painting apps.