This one is easy as “more is always better”, as long as you can use it effectively. While 720p cams were the norm in the recent past, advances in web conferencing software, video compression, imaging chip cost reductions and network bandwidth improvements have placed the benchmark squarely on 1080p-30 (1920x1080 @ 30Hz). This means that you should make sure that your camera is able to natively capture this resolution. This is the resolution typically used today by high cost hardware solutions, like Cisco, Polycom and Lifesize, so the images you capture for web conferencing will be right on par with these high-end solutions.
Cameras typically offer 2 types of zoom, with some offering both. Optical zoom is the only one that matters, as digital zoom basically robs you of resolution by simply cropping the image to show the “zoomed” pixels only. True PTZ cameras will have optical zoom with a motorized lens that adjust for wide and telephoto shots. The amount of zoom, typically specified, for example as “3x” indicates the variation available as the lens distance from the imaging chip is adjusted. While this gives you a rough idea of the amount of zoom available, a better and practically useful specification is the Horizontal Field of View Angle (HFOV) range. This is typically specified, for example as “5 degrees to 45 degrees”. This range, (if accurately specified by the mfg/marketer!) should allow you to figure out exactly what any camera will capture throughout its zoom range.
Where attendees are close to the camera, will need a wide angle HFOV. For instance a camera with a wide angle of 90 degrees will capture anything within a field twice as wide as the distance from the camera. This would effectively capture people seated at the front of the table. A camera with a wide angle of 45 degrees will only capture within a field that is 82% as wide as the distance from the camera. This is only 41% of the wider camera image and would not capture people seated at the front of the table. See the graphic below for examples
Where attendees or presenters may be far from the camera, will need a narrow angle HFOV. For instance a camera with a tele angle of 5 degrees will capture an image 26” wide at a distance of 25 feet from the camera (e.g. the head of a Boardroom table). This allows a good headshot with great focus on the speaker. A camera with a tele angle of 22.5 degrees will capture an image almost 10 feet wide at the same distance. This would not produce a headshot of any type and prevent focusing attention on an individual speaker. See the graphic above for examples.