Java is a fully fledged application programming language, which depending on your previous programming skills, can be easy to learn, or downright tricky. If you have no programming experience and you want to learn a decent language, then java can be a great choice - it can be much easier than C/C++ (mainly because there is no memory allocation in java, and java also has the String object already built in !). If you know C/C++ then stepping into java should be a doddle. But you need to work out what you want first ... to learn java from scratch is by no means a small feet ! I've been programming it a year, and I still consider myself a novice.
Anyway, I'm rambling. To sum up ... if you dont already know java, and you have no programming experience, then as JavaDude32 said, a scripting language like javascript (in no means related to java) with some HTML may be the best choice, as you can get results quicker. But if you're willing to put the time and effort in, then java is a good choice - as javascript is shite (in the longrun). But then you have to remember that to do anything half decent on the web with java requires knowing JSP, XML, HTML ..... anyway, good luck.