* Lean Java basics very well. SCJP book by Kathy Sierra, would be a great starting point.
* Read specifications from SUN. (
Servlet specification,
EJB specification etc). This is a key point, I started reading it very very late in my career.
* Set your browser homepage to any java related site like theserverside.com or javaworld.com. You may end up reading some good articles.
* Learn some design
patterns. Get one, Head First Design Patterns book and read.
* Have some understanding of protocols like TCP/IP, HTTP etc.
* Try to develop a friends circle where you can discuss and share the knowledge that you acquire.
* Try to get a mentor in your present company.
* Try attending some local company interviews to measure your knowledge.