Create Demo Video for the site

hi, we have got a portal for which we need to get demo video made which we will put on various places including youtube..the various features of the site will be shown in this video so that users can understand how to use the site.. the video may be of about 10 minutes duration and broken into two or three videos.. only those who have previously done this kind of job may apply.. we shall provide the name of our portal to qualified developers.. pl also provide links to your previous developments in this regard