In the menubar, Click Tools >> Options... >> Video Settings >> No one.
I'm new to Skype. When making or receiving calls, can I choose weather or not to be seen?
If you make a call and select "Call" rather than "Video Call," it won't start your video.
Likewise, when answering a call selecting "Answer" rather than "Answer With Video" will not start your video.
In either case, once on a call you can always choose to start your video manually by clicking on the webcam icon on the Skype toolbar at the bottom of the video window.
We are on Windows 8 and the Skype page does not have "Call" or "Video Call" on it. It just has the camera icon and telephone icon. When we answer by touching the video icon we only get voice and no video (for us or the caller) and video icon shows "locked". When we touch the locked video icon, it will not unlock.
If you're using the "Metro" version of Skype from the Windows store I don't have any experience with that. However, if that's the case you might try the "desktop," or traditional version, which should still have the features I described.
You can download the full installer for the desktop version here: