Javascript has nothing to do with Java - the four-letter tag they share just confuses issues and is really only there for marketing reasons. Netscape released JavaScript two years ago as a scripting language for the Web, closely tied with HTML and built directly into the browser. But while "Interactivity" is often a much abused term, JavaScript is a good way of adding a lot more of that interactivity to your Web pages - particularly if you've mastered HTML (and/or a programming language such as BASIC).
For the bewildered or befuddled, this 12-part tutorial by Nick Heinle is one of the best I've come across in a year. Nick is a JavaScript veteran, especially measured in "Web years", and I still remember the first time I bumped into his superb collection of scripts (or "the Scriptorium") at his Web site (now at http://webcoder.com) all of 18 months ago.
The CD-Rom includes all the book's scripts and a trial version of Infuse for Windows (I admit: I haven't tried it yet). But a worrying note is the errata sheet - at least 10 mistakes. It's a sloppy sign in an otherwise great debut by - wait for it - a 17-year-old who doesn't even leave secondary school until next summer!