Here is a very simple example, I leave it up to you to research some the classes:
java.awt.Panel panel = new java.awt.Panel();
java.awt.Graphics g = panel.getGraphics();
g.drawImage(Image, 0, 0, width, height, bgcolor, ImageObserver);
The to 0s represent the x and y coordinates to start with, the width and height tell java how large to paint the Image and the bgcolor is the background color. The ImageObserver can be the applet.
Sun Certified Programmer for the Java2 Platform