Enterprise Web Design

I am a budding Computer Science major who has just finished his first year at the local college.  I have completed all the university-transferable introductory language courses offered (C++ and Java).  Never mind the language choice, I wasn't taught anything beyond, "This is your input.  This is your output.  This is your class.  This is your ENTERPRISE-level single-purpose line-saving enhanced for loop."

My mother, who is paying my way through college, is expecting to see returns.  She has asked me to create a website for her start-up business.  Of course I don't know how to do that.

And this, dear /prog/, is why I need your assistance.  If you could just be my guiding hand here and point out books, websites, good languages to start in, software, anything a novice web designer might find useful.

Yes, I have read my SICP.
No, I only understood about a quarter of it.
Yes, of course I'm going to read it again, but at the moment I must place priority on the material world.

And for the trolls, I do intend on taking everything said in this thread seriously, so please refrain from "trolling" as I will no doubt end up believing it.

What's so special about web apps?

HTML is just a markup language. CSS is a presentation language, and Javascript is a client-side scripting language. If you know them, you can make any (static) web site.

Pick any general-purpose language and you can generate content dynamically (HTML, images, CSS, js, whatever). Input is the GET/POST request, and the output is whatever you need it to be.

There are frameworks for various languages which simplify the task considerably, or dumbify it so that anyone can do it.

However, designing web sites is not a programming job, it's Art, so you should get someone else to do it, unless you want to do it yourself (has MDickie replaced the scientist in you with an artist?).