The Lecture Pattern
To facilitate speakers in giving talks, they need to plug in their laptop, know how long they have left etc
TL;DR: Make it as simple as possible for a person to step up, plug in, talk and leave.
The Podium: An ideal setup has a VGA, HDMI and mini stereo cable visible when you approach the podium, along with a podium microphone that is adjustable. The "magic" for making the display work should happen at the A/V desk in the back of the room.
Speaker Time Notification: Ideally, the time left for a speaker should be on a very large clock visible in the back of the room that begins counting down when the speaker starts talking. However, most of the time you will have a volunteer with cards. These cards should read "10 Minutes", "5 Minutes", "ONE MINUTE", "STOP". Anything else is confusing for many speakers, many of whom are already nervous about giving their talk and may not have had times.