you need at least the following:
1. - J2EE: include the j2ee.jar (lib directory) into your classpath
2. - get the properties for the initial context from the EJB provider.
Depending of the EJB container, you may need some more jar libraries in your classpath.
Any EJB tutorial also contains client examples addressing an EJB. You may also check my EJB tutorial
(somewhat incomplete, but it may cover your questions).
Finally, you question relates to J2EE technology. When you need any further help, you might get it faster when posting in the EJB section of this forum.
Hope this helps.