To blackwhitebuyer
If you are preparing IELTS to migrate to Australia, you should be classify as "general", its not so hard, i saw my friends materials before, i am thinking may be that should be easy enough for you, if you are using English at work place. Are you thinking of taking the test in Taiwan or Australia? If you are going to take the test in Australia, may be it will be slightly harder, because of the speaking accent. If you do take in Australia, you got to be prepare the examiner will ask you about local events in Australia etc, such as political issues, if you dont live there how can u answer it?
My suggestion is to take the test in Taiwan, because my friend said you will get better mark in Taiwan, some even fly back to Taiwan to sit IELTS.
To be honest, its unlike TOEFL, not really much you can prepare, because no pattern to follow, may be try to memorise more vocabularies that should be ok.
Listening and reading (from memory, because i took it about 6 years ago) are all of multiple choice, writing i think you have to write 2 essays. Its not that hard, then it comes to speaking, you will have to have conversation with the examiner face to face.
I did went to those IELTS preparatin class before i sit them , ( i took academic test), but its kind of waste money, if you used to be a students you will know techniques to pass it.
Hopefully this helps you