If you're learning how to hand-write HTML from scratch, then nothing beats a good text editor... TextEdit, BBEdit, TextWrangler, etc. If you can't write and understand HTML by hand, then a WYSIWYG editor like Dreamweaver (in some respects) won't do you any good.
What does the curriculum look like for the web design class -- are you required to write and understand HTML? JavaScript? If you can give me more insight into how the class is structured, perhaps I can recommend a good program to assist with your class.