Here's my first draft, please critique:
You’re about to make your first post in the forums. If you’re asking for help, please consider reading our ‘how to help people help you’ page before you post.
How to help people help you.
First, can you help yourself? Many common problems are frequently posted in the forums. Try search and you may go right to the answer. Also try the reference, tutorial and playground areas of the site. Still no joy? Time to ask for help.
People asking for help often post a rather brief description of their problem. The people on the forums are keen to help, but sometimes are unable to without teasing out additional details. Providing them up front will get you help more quickly. Generally, what helps are these things:
• Your code, the entire sketch
• A schematic or description of your circuit
• A brief description of what your project is intended to do
• A description of your problem, including what your system is doing and what you expect/want it to do instead.
• Things you’ve tried to resolve the problem and the results of these.
It may also be useful to know which model of Arduino you’re using. If your code doesn’t compile, provide the error messages you get.
Once you have written this down, you may very well find that organizing your thoughts has given you new ideas about what’s wrong, if not please post.
Posting your code
When you post your code, make sure it’s between code tags – the forum software may turn parts of it into smilies otherwise. Format it in the IDE using T to make it easier to read. Unless you’re posting for help with a compiler message, be sure that it compiles.
Post all of the code, even if it means you have to provide it as an attachment. It makes it very difficult to help debug an issue if you just have a fragment of the code. Even if you think you know the general area where the problem is, you’re handicapping folks by not providing the whole thing.
Schematic
If you can, use Fritzing or other free tools to draw your circuit. Otherwise, at least give a description of what you’ve done. Provide part numbers and links to datasheets of any components that are more complicated than a resistor.
Project Description
A single sentence will often be enough, a little more if it’s a complex or unusual project. For example, “I’m trying to control an RC toy car with an on-board UNO” is plenty.
The Problem
Describe what you’re trying to make the project do e.g. “I’m trying to measure temperature with an XYZ sensor and send it to my web server”. Tell us what actually happens – “The temperature is read and sent to the web server, but it reads low by five degrees compared to other thermometers”.
What have you tried to resolve this?
Here you can help to eliminate suggestions that you’ve already tried – e.g. “I replaced all the components in my circuit with new ones – no difference” It’ll give the reader a feel for how far down the debugging road you’ve gone.
edit: formatting