I’ve begun learning Zbrush.
Rather than scrawl my notes on a piece of paper, I’ve posted them here.
PRIMARY BRUSHES:
Hit these keys in sequence (not all at once) to navigate the brush menu quickly.
B S T   -   BRUSH STANDARD
B C B   -   CLAY BUILD-UP
B D S   -   DAM STANDARD
B T D   -   TRIM DYNAMIC
B M V   -  MOVE BRUSH
Hold SHIFT while using any brush to SMOOTH your mesh.
OPERATIONS:
Keys and key combinations.
CTRL+D   -   ADD SUBDIVISIONS (MORE DETAIL)
D   -   CYCLE THROUGH SUBDIVS  ↑
SHIFT+D   -   CYCLE THROUGH SUBDIVS  ↓
SHIFT+F   -   SHOW WIREFRAME