Designer Robert Zipprich sends us a list of commands that you can use in AutoCAD with your mouse. "These AutoCAD mouse commands come standard out of the box as listed below, but they can be customized."
Middle Button = Pan
Shift+Middle Button = Orbit
Ctrl+Middle Button = Swivel
Left Button = Select
Shift+Left Button = Remove Selection
Shift+Right Button = Osnaps Menu
Ctrl+Right Button = Osnaps Menu
Notes from Cadalyst Tip Patrol: The mouse is likely the most commonly used form of input when using AutoCAD. A standard mouse has three buttons: left, right, and center (or the scroll wheel). Each of these buttons functions differently, and in true AutoCAD fashion, each one can be customized (with the exception of the left button).
To customize the buttons, open the CUI, browse to the Mouse Buttons section, and edit the options as you see fit. There are options for using the Shift key, the Ctrl key, Ctrl+Shift, and the standard click.
For even further productivity, many CAD users move up to a five-button mouse or a product such as the Belkin Nostromo SpeedPad n52 programmable gamer device or a programmable 3D mouse like those from 3Dconnexion.