I'm not sure that I quite understand your question. Do you want to learn HTML and CSS (a necessity today) or do you only want to focus on design? There are plenty of ways (and jobs, if that's what you're interested in) to do that.
To get started, I would recommend just going through sitepoint's HTML reference. I would recommend starting with HTML Basic Concepts (bottom left of the reference) and then reading through the HTML Elements section. Hopefully you'll find it interesting.
In terms of design, your graphic design training will help you with that. I recommend the book The Principles of Beautiful Web Design by Jason Beaird (Sorry about the underlining for you MLA7 buffs). It's a fantastic book that will get you started. You can get it from Sitepoint or, and this is better in my opinion, just check it out from your local library. Hopefully, they'll have it.
After that, use the forums! They're great for any problems that you run into.
Finally, build a website. Not with a WYSIWYG editor, but with hardcore, HTML markup. I'll let you look up WYSIWYG, if you don't know anything about it.
Good luck! Feel free to PM me or any of the staff (I sure hope they'll let you pm them) if you want any help. I'd be happy to talk to you in more depth (digitally, that is).