[trill]

Have a look at Java's own Applet tutorial, Lesson: Applets (The Java™ Tutorials > Deployment)

Code snippets you'll want to look at:

Code:

<applet code=HelloWorld.class width="200" height="200"></applet>

Code:

import javax.swing.JApplet;
import java.awt.Graphics;

public class HelloWorld extends JApplet {
    public void paint(Graphics g) {
	g.drawRect(0, 0, 
		   getSize().width - 1,
		   getSize().height - 1);
        g.drawString("Hello world!", 5, 15);
    }
}

Also Java's API is invaluable. Familiarize yourself with it and it will help you solve many problems very quickly. Java 2 Platform SE v1.3.1

Java tutorial site: The Java™ Tutorials

Usually when I need to find something Java related I head to Google, search: Java api 'whatever' and will find a related document in the api files.
Example: for this thread a googled: Java api Applet and that tutorial was the first link.

Greetings.