Transforms

Free Transform  //    Ctrl + T, Edit/Transform
Drag a corner, or anchor point, to scale
Hold SHIFT while dragging to constrain proportions
Hold ALT + SHIFT to scale from pivot point
Hold CTRL and drag a corner to distort
Drag inside the bounding box to move
Drag outside the bounding box to rotate
Moving the middle point will scale the layer in perspective
Right click to reveal more transform options:
Place, Cancel, Scale, Rotate, Skew, Perspective, Distort, Warp, Rotate, and flip.
Rasterizing the Layer will reset your transform bounding box