No. You don't need NetBeans for this.
NetBeans is an IDE (Integrated Development Environment) It is a tool used to help write java programs. You can work without it quite easily - even just using a text-editor like notepad (cringe)
What you need to run JSP pages, is a JSP server (eg Tomcat, Resin...)
Feel free to download NetBeans (or any other IDE). It can be useful, but is by no means a necessity. There are a bunch of threads debating the pros/cons of different IDE environments on this forum (NetBeans vs Eclipse vs IntelliJ...)
Cheers,
evnafets