From BlenderWiki

Basic Manipulations

This section gathers all basic transformations and manipulations in 3D Views:

• Grab (move) elements.
• Rotate elements.
• Scale elements.
• Snap elements to something (geometry, grid, etc.) during transformations.
• How to control the precision of the transformations.
• Make transformations by typing numbers rather than moving the mouse.
• Reset object’s transformations.