The Music you purchased from iTunes is protected by drm protection, that's do not need you play the Music/Video to anywhere. So,if you want to share the media files, you shoule remove the drm protection fist.
here is a software can remove the drm protection and convert the media (Music or Video like m4a,wma,m4p,wmv,asf etc) files to any other types like mp3,3gp,mp4,wmv ect, that is Daniusoft Media Converter Pro, download it here: http://www.dvdvideosoftware.org/daniusoftmediaconverterpro.html .
For your requirement, you also need a software to burn the video to DVD, so also need a software called Xilisoft DVD Creator: http://www.dvdvideosoftware.org/xilisoftdvdcreator6.html


