This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
To include your JAR in the classpath,
1. Right-click your project, select Properties.
2. Select Java Build Path -> Libraries
3.1 If your JAR is in your project directory structure, click "Add JARs..."
3.2 If not, click "Add external JARs..."
4. Select your JAR, click open, click ok.