Mouse Controls:

Command Button Modifiers Tool Cursor on
Create Brush left 2D - nothing selected
Select left shift+alt 2D/3D - any object
Toggle Select (aka XOR) left shift 2D/3D - any object
Move selected objects left Translate 2D/3D - manipulator
Rotate selected objects left Rotate 2D/3D - manipulator
Scale selected objects left Scale 2D/3D - manipulator
Move selected objects left QE 2D/3D - selected objects
Resize selected objects left QE 2D/3D - outside selected
Place clipper point left Clipper 2D
Move clipper point left Clipper 2D - Clipper point
Select Texture left Texture Browser - thumbnail
Toggle free-move camera right 3D
Move 2D View right 2D
Zoom 2D View right shift 2D
Position 3D Camera in 2D view middle ctrl 2D
Angle 3D Camera in 2D view middle 2D
Copy face texture middle 3D - brush face
Paste face texture middle ctrl+shift 3D - brush face

Toolbar Buttons:

Command Button
Mirror Selection around X-Axis
Rotate Selection 90 degrees around X-Axis
Mirror Selection around Y-Axis
Rotate Selection 90 degrees around Y-Axis
Mirror Selection around Z-Axis
Rotate Selection 90 degrees around Z-Axis

Keyboard Shortcuts:

Command Button Modifiers Tool
Open Map File o ctrl
Save Map File s ctrl
Toggle 2D view angle tab ctrl
Deselect All escape
Invert Selection i
Delete Selection backspace
Clone Selection spacebar
Copy Selection c ctrl
Paste Selection v ctrl
Undo z ctrl
Redo y ctrl
Toggle Face Mode on/off f
Toggle Edge Mode on/off e
Toggle Vertex Mode on/off v
Translate Tool w
Rotate Tool r
Scale Tool
Clipper Tool x
QE Tool q
Apply clipper plane to selection enter Clipper
Apply clipper plane (keep both sides) enter shift Clipper
Toggle Grid on/off 0
Set grid to 2^(N-1) eg. 2 = 2unit, 3 = 4unit, 4 = 8unit 1-9
Snap Selection to grid g ctrl
Convert Selection to a new N-Sided brush 1-9 ctrl
Move 3D Camera forward uparrow
Move 3D Camera backward downarrow
Rotate 3D Camera left leftarrow
Rotate 3D Camera right rightarrow
Move 3D Camera up d
Move 3D Camera down c
Rotate 3D Camera up a
Rotate 3D Camera down z
Move 3D Camera left ,
Move 3D Camera right .
Merge Selected brushes u ctrl
Subtract Selected brushes u shift
Toggle Entity List l
Toggle Entity Inspector n
Toggle Surface Inspector s
Toggle Patch Inspector s shift