To maximise the helpfulness and efficiency of using these forums for troubleshooting your Mac, there are a few basic guidelines and tasks that you may wish to undertake before creating a new thread as well as information you should include in the thread, if it comes to that.
First off, use the forum's search function to find if there is already a relevant thread that may answer your own question or alternatively, provide you with some techniques to try. As always, be intelligent with your search terms and parameters. Including words like Apple and Mac is pointless because there will be such a large abundance of results.
Secondly (courtesy of frankblundt), make sure you post your question in the appropriate forum to better your chances of having a resident expert see your thread.
Thirdly (courtesy of vikas soni), be specific with the thread title. A title like Help will not be as easily recognised by our resident gurus.
Fourthly, find out basic information about your machine. Tell us what sort of Mac it is, what operating system it is running and some basic hardware specifications. All these can be found in System Profiler, an app in the Utilities folder.
Fifthly, tell us what the problem is. Remember, be specific! The more detail, the better.
Sixthly, outline how long you have been having these issues and what changes you made before the issues arose. Include details, even if you think they may not necessarily relevant.
Seventhly, tell us what you have already tried in terms of your own solutions to this problem.
Eighthly (nearly there), once some responses to your thread start accumulating and you start trying some of the different techniques being provided, remember to answer each post with what the outcome was on your machine. If a technique worked, post a response saying so, such that future readers of your thread know this.
Ninthly, remember that this is a forum. There is no mechanism in place to ensure you are getting valid or safe help so use some of your own initiative as to whether you want to try a radical technique. If you are uncomfortable with a solution, say so and hopefully another member will be able to provide a simpler explanation or an alternative for you. Generally speaking, bad advice is rare on these forums, but be wary all the same.
Tenthly (courtesy of Blue Velvet), be patient. Don't bump your post within twenty minutes just because no-one has offered up a response — those online may not know the answer — and don't post duplicate threads in order to draw attention to your predicament. It splits the discussion and if duplicate threads are spotted, they tend to get deleted by the mods.
Eleventhly (?) (courtesy of Blue Velvet), be courteous. A small thanks can go a long way and recognition of the effort that people are putting in to answer your questions and solve your problems will make your MR experience that much more enjoyable.
For those of us who are concentration span-challenged:
Search for threads or guides containing similar problems.
Start your thread in the appropriate forum or sub-forum.
Use a specific thread title.
Find and post machine hardware and software configurations.
Tell us your problem, and be specific. What is happening to your machine?
How long has this been happening? What changes were made just before this started?
What have you already tried?
Respond to all posted advice with details of what happened.
Be wary of the (very) occasional bad advice.
Okay, now everyone can chip in and tell me all the details I've forgotten.