Sometimes the perspective camera in Maya rotates (ie tumbles/orbits) around its own pivot point when the desired behaviour is to rotate around an object. When pressing ‘f’ does not fix the issue, or when trying to manually reset the centerOfInterest attribute of the camera, the best way to fix this problem is by selecting an object, and then on the viewport menu: View > Look at selection.

… in Maya, you can quickly get the dimensions of a selected object (or objects) by activating the Universal Manipulator Tool (CTRL+T)? The tool itself has numerical indicators on all three axes.