It depends upon their computer. You don't need a Mac, modern Windows PCs are perfectly good for creative tasks!
If your friend has a PC, Windows Movie Maker 2.1 is free with Windows XP SP2. It's easy to use. Although its features are limited, it may be enough for this first, simple project.
The edited file can be saved to the computer's hard disk and then "authored" and "burnt" to DVD using whatever DVD burning software they have on their PC - eg. Nero, Sonic, Roxio etc.
Serif makes a more advanced, more flexible Windows program: Serif MoviePlus. The previous version, version 4 is very stable; the current version 5 has much improved features.
See:
Serif MoviePlus5.
Some people report that Pinacle can be unstable.
If your friend has an Apple Mac, they should already have iMovie or equivalent. This should do the job. Other people have already suggested more ambitious, more expensive alternatives.
If your friend runs Linux, there are some open source video editors.
Note: Video editing needs plenty of hard disk space; also, video rendering & encoding need patience and/or CPU power.
Each hour of miniDV digital video occupies about 13GB of hard disk space.
Rendering & encoding video on a fast PC often takes two or three times the duration of the video.
Editing digital video is addictive!
See:
Sri Lankan Videos.
Richard