Meve,
Drop the pictures on the timeline, and press the event pan/crop button on each clip. This will bring you to a control window where you can easily resize and move the picture. Just grab a corner and drag in or out while watching the image in the preview window. If you want to resize multiple pictures to all the same size, make the adjustments to the first one, then highlight the clip, right-click, and select Copy. Next, select all the remaining clips on the timeline, right-click, and select Past Event Attributes. Obviously if you're trying to fit a portrait orientated picture on a 4:3 display, you'll have to crop some off the top or bottom. Using the pan/crop window you can adjust the picture's location so that the area of interest is on the screen.