Skype has a number of screen sharing options. You can share:
You can share your computer desktop and everything on it. Any program you open while sharing your desktop will be seen by everyone in the meeting. This also includes notifications for emails or IMs. Be aware of what you have open and what may pop up if sharing your desktop. Also make sure your computer background is work appropriate.
To share your desktop:
If the attendee view doesn't show by default in your meeting space, unhide the stage.
To hide/unhide the stage: