Best approach for self-taught developer looking for job?

I'm in the same boat as the OP except I'm just about to finish high school with 2 years of part-time experience in a web dev shop.

The main problem I'm having is not even being able to land an interview. Where should I look for a dev job in Australia?

You'll probably need to start with a small company, bigger companies usually aren't willing to give someone their first "big break". I started out just doing my own projects and then did some work for relatives, etc, then, finally I was able to find someone who was willing to hire me a few hours a week to do remote development. From there I just kept incrementally jumping to the next better opportunity I could find. Its not necessarily the smoothest path but you can progress quickly if you keep pushing yourself. Basically, don't think of anything as being beneath you as long as its related to development, take the first job you can find with a company that will even give you half-time to where you can go into an office each day and work. A lot of companies are weary of letting people "short on years" work on development so its an uphill battle, but even working in a QA position could lead to a solid developer job as you usually can expose yourself to the application's code (some QA guys do and want to become developers, some don't). If you're a QA guy who reads code and finds bugs then... to the next job you apply to you can say you were a junior developer, and so on

Well, I've been working as a full time dev for 3 years now and never went to college.

What I did was start low as a jr. system admin for linux systems. I'm not very social so I never made 'connections' so I hade to improve my skills. So from jr I went to sr, and within a couple of years got my first job as a jr. dev for a small company.

It's at these kinds of jobs that you will learn the essentials:

MVC Databases HTML/CSS/Javascript Message Queues

From here, it's up to you to keep improving your skills and building projects. Managers don't like github profiles, so I highly recommend you have your own app (not just a website.)

From there you can move on to things like: Mobile Apps Function Languages Socket Servers Low Latency Systems

Of course, always make sure you study and learn the basics. Such as basic sorting algorithms, working with bits/bytes, etc.

And so on.

Work for $10/hr.

I'm a self taught developer as well.

I started with the front end because I had a decent design sense and attention to detail. If you can care about pixel perfection, I think it's a good route. JavaScript, HTML, and CSS aren't the most difficult technologies to start with, and you get a little more leeway to make mistakes or write sloppy code in the beginning, learning as you go.

It's a good time to be doing this. There is need for developers enough that if you can prove that you're smart, a mid-sized or smaller startup may take a risk with you.

Try putting up a personal website. Set up your own server if you can, write your own code, and get something up showing what you can do.

At this point, do whatever you can to show that you've taught yourself a decent amount. You want to prove that you can learn, not so much that you're already a pro.