Selection Tool
shift + S
Your default tool. Used to select vertices, edges, faces, meshes, objects, and groups.

Translate Tool (move)
T
Move the selected object in different directions. You can use the arrows to drag the object to a different location.

Rotate Tool
R
Rotate the selected object on any axis. The rotation is snapped to a defined angle. You can change the angle on the bottom right.
You can also press and hold the ctrl key and drag to rotate without any snapping.

Scale Tool
E
Scale up or down objects. Also works for props.

Pivot Tool
insert
Change the center pivot point of an object. Can be useful to translate for example a 90 degree tunnel. This is a temporary change, unless you use 'Set Origin To Pivot'.
