Ok, at that size you're looking for more than just a simple webcam and laptop. A few of several integrated solutions out there:
http://www.clearone.com/solutions_media_collaboration
http://www.polycom.com/hd-video-conf...ect-offer.html
http://www.cisco.com/c/en/us/product...ing/index.html
http://www.vaddio.com/category/ucc
https://www.qsc.com/systems/solutions/conference-rooms/
and I'm sure there are other hardware options as well at various budget levels.
Depending on the acoustics of your room and how many people, you might also consider an audio processor with acoustic echo cancellation and external mics, though some of the more basic solutions above have external mics that you can put on the table that would probably be more than adequate for your size of room.
My job specializes in designing and programming the audio part of these kinds of conference systems in really difficult and challenging rooms, some with really horrendous acoustics--what is it with architects and their fascination of using untreated window walls in conference rooms?
I just completed a system that uses these steerable mics
http://www.shure.com/americas/produc...ray-microphone
with the QSC solution listed above. The client simply brings their laptop into the room, plugs in the USB cable to the AV Bridge, and HDMI to a flat screen on the wall, and now they have a skype or webex solution complete with PTZ camera for a fraction of what it used to cost using a professional codec and camera system. Pretty slick! And yes, it has an untreated window wall, and I got the mic steered to minimize it's effect on the audio pickup within the room.