Note: This is ONLY if you wish to upload a video to the website directly instead of a service like youtube.com or vimeo. You can only do this if your video is under 35mb .It is still advisable to use a video service like vimeo (preferred) or youtube because their servers are optimized for video streaming.
First make sure your video is in mp4 format. This is the best format for the web, since flash is not available on every device.
If your video is not in Mp4 format, you may download Miro Video Converter to convert your video.
Once your file is converted to an mp4, make sure it is UNDER 35mb in size.
Go to the page you want to insert it in to and click the EDIT PAGE button at top right.
Click inside the page editor where you want the video to go.
Click the INSERT IMAGE button above the wysiwyg editor. Drag your video into the media manager and then click on it to select it, once you are done uploading it.
Click INSERT INTO PAGE button at bottom right of the media popup window.