Step 1:
Select the iDVD tab.
Step 2:
Select a clip in your timeline that you would like to be a menu option
on your DVD screen. Click the "Add Chapter" button.
Step 3:
Enter a Chapter Title.
Step 4:
You may remove chapters by clicking on the "Remove Chapter"
button.
Step 5:
You may rename Chapter Titles by double-clicking the text.