how do i add a picture to a movie file. When i open my movie folder i would like to be able to see a picture

To quote this page:

http://support.apple.com/kb/ht2487

Put color and pictures in windows

[can't copy image]

You can add a background or paint windows with color. If you display a Finder window in Icons view, you can display a picture as the window backdrop or change its color.

1. Select a folder whose contents you'd like to see all spruced up and double-click it to open it.
2. From the View menu, choose as Icons if the window isn't already in Icons view.
3. From the View menu, choose Show View Options.
4. To put an image in the window, under the Background header, select the Picture radio button, then skip to step 6. To change the background color, select the Color radio button.
5. To select a color, click the color swatch that appears next to the Color radio button, and select a color in the resulting Colors window.
6. Drag a picture to the image box that appears next to the Picture radio button.