There are many ways to do this. Here's one one:

1. Determine the length of the insert. Example 1 minute.
2. Put the timeline cursor on the exact spot you want the insert to begin.
3. Do Ctrl A to select all the tracks, audio and video on the time line.
4. Press "S" for split the event.
5 Press "M" to create a marker (in case you get messed up. The marker doesn't do anything except mark the insert spot)
6. Click anywhere on the screen that is NOT on the timeline. This should de-select all events. (Note: Does anyone know a ctrl key or short cut for this?)
7. Holding the ctrl key down left click just to the right of the marker or where you split the clip on each of the video and audio tracks. Release the ctrl key and right click.
Chose "select events to end" . This should select all events to the end of the project to the right of the insert spot.
8. Pull any one of the events to the right and open up more than a 1 minute space.
9. Make sure that "auto ripple" is clicked off.
10. Drag the insert clip to the timeline where you want the insert to begin.
11. If all the events on all the tracks are still selected, pull any one of them back to the left to close up any remaining gap.

Whew! .. It's really simple but hard to explain if you don't already have a solid grasp of the concepts involved. Hopefully I didn't goof on the instructions. There are other ways and remember "undo" (Ctrl Z) will get you back to where you started.