Instead of downloading and using your own Selenium jars I would use [Maven][1].
Maven is used as a build tool and will download any dependencies you might need, like the latest version of Selenium

 1. Create Maven Java application
 2. Add in Selenium dependecy in the pom.xml

        <dependency>
            <groupId>org.seleniumhq.selenium</groupId>
            <artifactId>selenium-java</artifactId>
        </dependency>
 3. Start writing your tests

Blog post about getting using Maven and selenium with Netbeans: http://seleniumstuff.blogspot.de/2013/08/getting-started-with-selenium-maven.html

For creating and running tests use [jUnit][2], have a look at this example: http://testingbot.com/support/getting-started/junit.html Just ignore the Eclipse setup. Use the code :)


  [1]: https://maven.apache.org/
  [2]: http://junit.org/