In the video track, take the top corner of the last image of your clip. The mouse pointer will change into an arrow pointing both sides and a 90 degree sign. Hold the mouse button down and drag the corner inwards into your last frame, and you have your fade. The length of the fade depends on how far you drag the corner into the clip. Same applies for the beginning of the clip of course.

You can also take a second clip and drag it into the end of the first. That will give you a transition (flow over from one clip into the other).

Hope this helps
R