iDVD isn't officially supported on Mountain Lion, but many people have reported that it works just fine as long as you get iLife '11. Earlier versions of iLife may not work correctly. There are also alternative DVD creation/burning applications available. Search the web for "alternatives to iDVD" and you'll find a number of suggestions.
... Can someone please confirm that tyhis will work?
Yes, using iLife 11 and iLife 09, and iLife 08 has been reported to work as well.
Install and update it to iDVD 7.1.2: http://support.apple.com/kb/DL1414
The DVDs you create will play on a DVD player.