You are probably right, but if anyone knows how to type in a specific length, I'd like to know. ;>}

Two tricks:
1) Position the cursor where you want the transition to begin; you can move frame per frame using the arrow keys. Next drag the event until it snaps to the cursor.
2) Under the timeline, on the right hand side of the screen (above the preview screen), there are two numerical indicators. The one to the left indicates the position of the cursor. When you double click it, you can set the position by typing the numbers.

Hi Suzham,
Create a region, then double click it's counter and set it to exactly what you want time wise. Drag your clip over your newly created region, and start dragging the leading and trailing edges of your clip until it snaps into place. You can make your clip exactly as long or short as you want.
As for the transitions, create a region as long as you want the transitions to be. This will now be your template. Drag the template over your video clip until the right edge of the template lines up with the right edge of your first video clip, then drag your second clip over the first clip until it snaps to the left edge of the template, and just like magic you have an exact transition time every time. Let us know if this helps, and was clear enough to understand. Cin