NOTE: The following instructions are for iMovie '11. It may work a little differently in iMovie '09 (can't recall).
Firstly, zoom in on the project timeline so that you can see more thumbnails. To do this, adjust the thumbnail slider (just below the Project window) so that it's set to show, say, 1 second or half a second of video for each thumbnail.
Click on the start point of the section you wish to trim out. While holding down the mouse button, drag across the thumbnails until you've got to the end point of that section. The section will now be enclosed in a yellow border. Right-click (or Control-click) within the yellow border and, from the pop-up menu, select Delete Selection. That will remove the piece you highlighted.
If you didn't get the exact frames, you can still fine tune the edit. Before doing this it's best to set some preferences in the menu item iMovie > Preferences. In the General tab check the box "Display time as HH:MM:SS:Frames". In the Browser tab check the box "Show Fine Tuning controls".
Now in the timeline, click on the left/right pointing arrow (it's a fine tuning control) near the start or end of the clips you've separated. The end will be highlighted with an orange border. Drag the orange handle inwards or outwards and you will be able to adjust the clip end (or beginning) in increments of one frame at a time, up to one second of video.
John
Message was edited by: John Cogdell - added Note
