If you're planning to use the classroom or conference room projector with your MacBook Pro, there are a few things to go over.

HDMI and DVI connected projectors are ordinarily auto-detected by the MacBook Pro when connected and powered on.  In some cases, the auto-detect fails, and you may need to set them up manually.  It's surprisingly easy to do.

Go into System preferences (Under the Apple Menu)

Choose "Displays", This should show an "Arrangement" tab.  This is where the external projector is managed.  If "Arrangement" is not present, make sure that the projector is powered on, all cables are properly connected, and the projector is set to listen on the correct input.

For sound, Choose "Sound" in System preferences.  There is an "Output" tab.  In "Output" you can choose either the internal speakers, or "HDMI audio out".  HDMI audio out will send the sound signals to the projector.

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