Presentation duration is flexible. Generally they are in the 45-60 minute range, but have had them last between 30 minutes and 2 hours.
Meeting format is generally a "formal" meeting at 1pm, followed by show-and-tell, and then a short break before the presentation.
We normally record presentations (see Presentations link on the left), although if this is an issue just let us know and it can be skipped for your presentation.
Our meeting room has a screen and the club has a projector with VGA input. With advance notice we can generally have a member bring a HDMI to VGA adapter. The club also has a document camera which can be used to project demonstrations of small devices/objects as well, although it is not kept at the meeting location and needs to be arranged in advance.