How do I let visitors download videos from my site?

Go to the page where you want the download link to appear and make sure you are in edit mode.
Add a link to your page using 'Insert' –> 'Button link' button, or by adding a link to your text or on an image.
Within the Editor locate the 'Links' tab and select 'File for download' (folder icon). Clicking 'Browse' will launch the 'File Manager'.
If you have already uploaded your video file it will be in one of the folders that appear in the 'File Manager'.
FLV (Flash Video) files will be located in the 'Your Videos' folder while videos in all other formats can be found in the 'Files for Download' folder.
Navigate to the correct file, select the file and then click 'Use this'.
Lastly, click the 'Apply' button, before deciding on your final position for the link.
You can now position and scale the link object on the page and edit the text within the link using the Editor (for buttons) or in the text itself.