There is nice and short list of tips on hot to ask questions at LifeHacker. If you are new to the Internet, or if you are old and noone seem to ever answer your questions, go read that little article.
If it’s obvious that you haven’t put any elbow grease into researching your question yourself, folks are a lot less likely to help you – especially on mailing lists. Make sure you do a good faith run through the user guide and search the web before you waste other people’s bandwidth on an issue you can solve yourself.
There are times when web search won’t help because you don’t know the right terms that others have used to describe the concept. In those cases, say up front, “My Google skills failed me” or “I searched a few different combinations of foo and bar, with no success” or “I called customer service and they couldn’t help either.”
Show that you at least tried.