What kind of videos are you trying to add?
I have found that embedding "You Tube" vidoes is extemely easy. Just copy the code from You Tube and paste it in the editor where you want it (in CODE VIEW).
I have also had success uploading Windows Media files then manually writing the code. If you know how to write the "embedding code" then it is quite easy from Code View.
Keep in mind, if you allow JavaScript to be entered then this should only be done in a locked down admin area. Don't ever allow a site visitor this type of access (ie: forum posts, blog replies, etc...) as someone will hijack your site with XSS!
Good luck.