Choosing a web design program can be a confusing process for a budding web designer. There are so many different programs available that can all do the job, depending on what you want to do. Some programs are geared towards advanced users while others are better for the novice.
Popular programs like Dreamweaver are great products, that allow the user a lot of flexibility. There is a reason that DW and the like are so popular: they make designing easy. However, they come with a hefty price tag. Notepad and other text editors that usually come bundled in your operating system are free but not always best for the beginner.
Some factors to consider when choosing your software are: price, ease of use, and system compatibility. With some programs you will work directly with code, and it is great to jump right in and start learning what all those seemingly nonsensical symbols and lines of markup mean. Working directly within the HTML or CSS allows for much cleaner code with less errors.
Some folks are just not cut out for that route and do better with a "WYSIWYG" (what you see is what you get) editor. These programs allow you to design in an environment similar to that of a word processor.
A word on using "Word" and it's counterparts: It is possible to design in programs such as Microsoft Word and the like, but this is definitely not the way to go as word processing programs are meant for print and aren't up to par when it comes to coding. Not only are they not standards-compliant, but they add a lot of extra, unwanted "stuff" to your code.