Movement
WASD: move (or in Settings--> controls, change to AZERTY), or right mouse button click and hold, then drag to move. Hold shift while moving to go faster.
Q/E: Rotate camera
Mousewheel/page up or down: Zoom in or out
Free Cam Mode
F10: Enter/exit freecam mode
WASD: Move camera
F and C : Adjust camera elevation
Building
R: Rotate building
Shift + Click : place more than one of the building
B: demolish tool
R: Build network (last selected type: dirt road, urban road, or track)
X: copy building tool
Shift+X: copy building settings (hold shift+X, click on copy building, click on paste building)
I: Flatten ground
O: Raise/lower ground
Function Hotkeys
F5: Quicksave
F7: Quickload
F8: Top down view
F9: Toggle region lines
F11: Turn of user interface (great for screenshots)
F12: Take screenshot (Steam version only
Additional Hotkeys
H: center camera on headquarters
T: Tech Tree
ESC: close all panels, again to open menu
TAB: Cycle label modes: Settlements, major centers (HQ), resource labels, building labels, no labels.
ALT: Toggle production bubbles
Click truck: show truck information
G: toggle terrain grid
Spacebar: Pause/unpause
1,2,3,4: Adjust game speed