Listening - 8.5
Reading - 9.0
Writing - 8.0
Speaking - 8.5
Overall - 8.5
I was lucky to have been living in an English-speaking environment for a long time. This is a huge advantage.
If you are fluent with English, the exam is trivial. If you are struggling, it will really help to know how the exam is structured and what exactly is expected from you in each section. So, here is my advice section by section.
Note: to convert number of answers to IELTS grade, I used charts here: http://www.examenglish.com/IELTS/IELTS_Band_Scores.html
Listening:
The easy part:
You are allowed to make a lot of mistakes and still get a good IELTS score.
The hard part:
1. To get maximum points in EE, CLB 10, you need a score of 8.5. However, this allows you 3 mistakes, which is not too bad. To get CLB 9, you need a grade of 8.0, which allows 5 mistakes. To get CLB 7, which is the minimum for CEC (NOC A and O occupations), you only need the grade of 6.0, you are allowed 17 mistakes, which is a lot.
2. Nothing is repeated. The correct answer is said once and if you were not able to hear it, chances are you will not be able to answer the question.
3. It is easy to miss answer to a question and panic. This can cause you to miss the next one, which will make you panic more and turn the exam into a train wreck.
Advice:
1. Don't panic. You are allowed to make quite a few mistakes. If you did not get the answer to a question, either quickly come up with a reasonable answer that sort of sounds to what you heard or just leave the question alone. If you dwell on one question too much, you will miss the next one(s).
2. Go through practice tests online. Google "IELTS practice" and enjoy. Go through at least a few, so that you are familiar with the format and know what to expect. If you panic during a practice, no harm done. If you panic during the real thing, you can lose a lot.
Reading:
The easy part:
All the answers are right there in front of you. With enough time, getting 40 out of 40 should be easy!
The hard part:
1. There is little time. You need to be fast and thorough at the same time.
2. You are not allowed too many mistakes, though fortunately CLB 10 and 9 do not require too high of an IELTS grade: CLB 10, you need a score of 8.0. This allows you 3 mistakes, which is not too bad. To get CLB 9, you need a grade of 7.0, which allows 6 mistakes. To get CLB 7, you need the grade of 6.0, which allows 10 mistakes.
Advice:
1. You need to be fast when reading the text. Do not try to get every detail: just remember what each paragraph is about. You want to read the article just well enough to be able to get to the right paragraph when you read a question.
2. If a question is hard, move along. If you have time at the end, you can go back. All questions are worth the same, no matter how easy or hard. Last thing you want is to waste 15 minutes beating on one question, only to skip 5 easy questions at the end since you did not have time.
3. This is, in part, an endurance test. You need to be concentrated and efficient throughout.
4. Once again, online practice tests will help.
Writing:
I am not good at writing, so I can't say much beyond what alok4best said.
Keep in mind that the goal is to show your English, not to show your knowledge on the subject. Don't waste your time with trying to find the best possible arguments, go with what you can come up fast and instead focus on making sure all your sentences and paragraphs are well constructed, that the text flows, that you do not make to many spelling mistakes and that you do not mix "their" and "they're"
Speaking:
I'd say this is the hardest one to study for. Practice speaking English. Have as many conversations in English as you can. If you have a relative in Canada that you are talking to with over the phone, insist on speaking English.
Also, make sure you speak clearly. When people are nervous, they speak fast and quiet. This is bad. It is very important that the examiner can understand what you are saying, both on the spon and when they listen to the conversation afterwards (speaking test is recorded).
Speak slowly: this will make it a lot easier to understand you, though I know this is easier said than done. Speak loud: that will both make it easier to understand you and will force you to speak slower.
I hope this helps! ;D