I didn't do anything fancy to my CV. I'm self taught as well and had no previous design related jobs. I just put down that I've been freelancing. At my interview they didn't even ask about qualifications. The most important thing is your portfolio as that is ultimately what they judge you on (at least at my interview) and that they can see you have passion.
A good thing to do is list your skills (XHTML/CSS, Photoshop etc. and the level you're at with each skill) at the top of your CV as most employers/recruitment agencies get a massive amount of CV's and don't want to have to go through your whole CV to find it. My girlfriend used to work as a recruitment consultant and she says to keep it as short as possible. Maximum 2 pages, but if you can squeeze it in to one page it's better. In her agency they would hardly even read the CV's but just scan through and go straight to the relevant stuff like skills and work experience.
Also for design related jobs it's a good thing to put a bit more about yourself than you would normally. On a normal CV you'd just have hobbies/interests: football, Movies etc. But write a bit about why you want to be a designer instead. Try to get your passion through here. They were well impressed with that at my interview.
If you manage to get an interview make sure to ask a lot of questions about the company etc. It shows you're keen and have an interest in the company. Do your research, so you know everything about them. Firm handshake (but not too firm
). Smile, be friendly and you'll be fine.
Good luck!