Dreamweaver is great, but tough to learn if you don't know much about how to structure a web site. Try learning on FrontPage (it is probably already on your computer you use a Windows system). You will quickly outgrow Frontpage but it is easy to use and gives you a good footing to move to Dreamweaver. To make a really good site in Dreamweaver, you should learn Photoshop, and that is tricky.
So, in a nutshell, DW is great once you get some experience in FrontPage. Don't buy DW until you have a good idea what is going on with HTML and how to lay out a site. Good luck..