Another thing -- You can add chapter markers within iDVD itself. You can't place the markers with precision, but can add them at time intervals of every 1 min, 2min, 3 min, etc, so that you can fast-click through the movie instead of laboriously doing a fast forward. When you add the markers, a scene selection screen sub-menu screen will pop up, but you can select and delete the screen selection button if you don't want to use it. You can still fast-click through the movie by clicking on the fast forward or skip arrow.
EDIT: To add the markers in iDVD, single click on the movie's link icon in the main menu screen, and then go to Advanced/Add Chapter Markers. A selection box will appear showing the time interval options.