This week's book giveaway is in the OCMJEA forum. We're giving away four copies of OCM Java EE 6 Enterprise Architect Exam Guide and have Paul Allen & Joseph Bambara on-line! See this thread for details.
Regular java beans are just java classes that you write that must have certain things by convention. For example, they must have a set and get method for each public variable they expose. They also must have an empty constructor.
EJB (Enterprise java beans) are more complex and are used in Application servers such as JBoss. They have many features like remote usage, transactions management and much more.
For better explanation see here from just 2 days ago.