Apple Final Cut Express HD: Getting Started - Manual (Page 113)

Chapter 7 Adding Transitions 113
To add a transition from the Effects tab in the Browser:
m Drag a transition from the Effects tab in the Browser to an edit point in the Timeline.
Depending on the number of overlapping frames between the two clips, you can drag
the transition to start on, center on, or end on an edit point.
A transition
starting on the cut
A transition centered
on the cut
A transition ending
on the cut