From BlenderWiki

Transform Control

In this section we explain how to control:

• the amount of change of the transformation
  • Precision of Transformations
  • Numeric Transformations
  • Transform Properties
  • Reset Object Transforms
  • Proportional Edit

• the orientation of the transformation
  • Manipulators
  • Transform Orientations
  • Axis Locking

• the center of the transformation (Pivot Point)
  • Active object
  • Individual Centers
  • 3D Cursor
  • Median Point
  • Bounding Box Center

• a reference object to do the transformation
  • Snapping Transformations
  • Snap to Mesh