After a model has been loaded, the initial location of the Cursor is set to the look-at point - the geometric center of all visible geometry. The coordinates of the Cursor are specified with respect to the default frame: frame 0. However, if you have created additional frames, you can position the Cursor relative to the origin of a different frame. This is accomplished by selecting the desired frame in the Which Frame list in the Transformation Editor dialog.

You can easily reset the position of the Cursor tool to the default. See Reset Tools and Viewports for more information.

Positioning a 3D tool with a 2D device (the mouse) can be difficult. Multiple viewports are sometimes helpful in positioning tools since you can see the tool simultaneously from multiple vantage points.