With that type of an introduction, you might want to look at getting SCJA certified - it deals quite a bit with J2EE, J2ME and J2SE. My books on the SCJA exam might be a good point for getting more in depth with the technology.
For some free tutorials on developing EJBs and Servlets, or even just some Struts or Portlet development tutorials, check out some of my signature links. There are a bunch of free CBTs and corresponding source code that demonstrates how to create pretty much all of the core J2EE components, inclusing Servlets, JSPs, ServletFilters, Listeners, EJBs, MDBs, SLSB, SFSB, portlets, and even some admin stuff. And it's all free.