Mailing Lists vs Forums vs IRC vs Newsgroups vs Twitter vs ...
This debate is about as valid as the good old standard vi vs Emacs war.
Different people find each option appealing for different reasons, and similarly dislike some options more than others. It's a very personal thing. There is no one right answer - use the one you like best! That's what open source is all about.
IRC can get the fastest results, but can be quite intimidating to use, and the quality of the results varies with the quality and quantitiy of people in the channel at that moment. The perfect example of YMMV.
The web forums are arguably the easiest to use, and the easiest to search. Less technically minded people often find them more to their taste.
The mailing lists often have the more experienced users on them, and results are often high quality if terse.
Now, keep in mind those points are correct roughly as often as the statement:
Cats are usually smarter than Dogs
- try to figure it out on your own before asking the world for help
- try them one at a time rather than all at once
always be mindful to ask good questions
- post back the results of what you did and how it worked out so the next person has an easier time of it