Select, move and arrange layers

Select layers with the pointer or the keyboard, move and resize them, nudge them, and align, distribute and order them.

Select layers

Click a layer to select it. Shift-click adds a layer to the selection.
Double-click a selected layer to select the layer inside it under the pointer. ⌘-click (Ctrl-click on Windows) selects the deepest layer under the pointer at once.
Drag on an empty part of the canvas to select the layers the box touches.
Select all (⌘A) selects every layer at the level you're on. Enter selects the children, Esc the parent, and Option+Esc (Alt+Esc on Windows) clears the selection.

Drag a selected layer to move it. In a stack, dragging changes its place in the stack. Hold Space while you drag to take it out of the stack and put it where you drop it.
Drag a handle on the selection's outline to resize it.
The arrow keys nudge a freely placed layer by 1 px, and Shift with an arrow by 10 px. Layers in a stack keep their place.

Align left (Option+A, Alt+A on Windows), horizontal centres (Option+H), right (Option+D), top (Option+W), vertical centres (Option+V) and bottom (Option+S).
Distribute horizontally (Control+Option+H on a Mac, Alt+Shift+H on Windows) and vertically (Control+Option+V, Alt+Shift+V) space three or more layers evenly.
Bring to front (]) and Send to back ([) change which layer is drawn on top. ⌘⌥↑ and ⌘⌥↓ (Ctrl+Alt with the arrows on Windows) move it one step.

Copy, cut and paste with ⌘C, ⌘X and ⌘V (Ctrl on Windows). Duplicate with ⌘D.
Backspace or Delete removes the selection.
Copy style (⌘⌥C) and Paste style (⌘⌥V) copy one layer's look to others.