If you already know the Java language,
you should be able to learn JSP and Servlets quite easily. Rather than focusing on the language, you can focus on how to use Java for web programming. This, in my opinion, is much more fun than trying to learn object-oriented programming!
A servlet is just a special class, so the code looks like regular Java code. JSPs use their own tags, so you'll have to learn how to work with them. However, they're not difficult to use.
JavaScript is not the same as JSP. In our book, we cover how to use JavaScript for simple data validation on the client. There, you'll find that the syntax is similar to Java, but they are not the same. Compared to ASP, I believe JSP/Servlets is similar. Rather than using VB classes in the background, you use servlets.
To get started, I'd (obviously!) recommend our book. This will get you started. In fact, you'll actually learn quite a bit. If you have background in web programming, you'll speed through much of the book since you already know the basics of web programming.