I wholeheartedly believe that it is possible to become knowledgable in Java
within six months, as long as you're willing to devote the necessary time.
I began learning Java last year in an intensive 9 month program in Canada
that covers Visual Basic, Java, Oracle, some networking, html, etc. The Java
portion was only 6 weeks and although intensive gave me a good basis to further
my learning. By November of last year I was facilitating a Java course at
a technical college (only 4 months after I began learning it myself). Now
I work as a developer using java in NYC.
If you're interesting in learning more I'd recommend books like Deitel &
Deitel's "Java How to Program" (excellent for experiential learning) and
"Core Java" by Horstmann & Cornell (a good all-around reference). Sun's java
site (http://java.sun.com) has everything you need to get started plus some
tutorials you might find useful.
As for additional technologies, I think Dun was right. It seems the key in
the IT world is diversity and an eagerness to learn new concepts (always).
I've found Java to be in high demand especially for web technologies like
JSPs and connecting to back-end databases. However I've also found that Active
Server Pages (ASPs) which use VB Script are as highly demanded and for a
beginner, easier to learn. I'd consider going down that road as well. Good