How to install iDVD
of iLife 11
You can purchase it from the Apple Store on-line, not to be confused with the App Store, and it will arrive in a couple of days.
Insert the DVD and iPhoto, iMovie and iDVD will be installed.
All that said, you have a Macbook which came with the iLife suite on it. Did you remove it or is it still there?
If it is, then it will still be there when you upgrade to Lion