One of the coolest things about dA is it's not just for sharing art, it's for sharing ideas about art. If you're stuck on a piece, or you'd like to learn to how to do something that just hasn't been clicking in tutorials or class, the art-related forums are a great place to look!
But the best part about the forums is also the riskiest part: anyone can answer! Which means you'll get opinions which contradict each other, 'industry facts' from people who heard it elsewhere on the internet, people who don't quite understand your original question...it's a mess!
So how can you back up all that different advice, or alternately open with a question that won't be confusing?
Ignoring for a moment that I basically worship Google (hey, you try growing up with a 1000-page reference book as your only source of random facts), it's is an awesome, flexible tool.
Just drop your question into Google and see what you find! A lot of experts (or just all-around smarties) have blogs or tutorial sites where they discuss how they do stuff, so if it's a person whose work inspires you, their advice may be even more useful.
Of course, Google can't tell you how you might resolve a plot twist, and Google won't offer you the chance to debate whether trying to duplicate traditional techniques in Photoshop is a good idea, but it's a fantastic starting point, especially if you're having trouble wording your question! (Remember: forum posts can't be edited or deleted; only locked, if you request it in #help, so if you make a mistake, it's there forever. Well, a week, anyway. Shh.)
In short, Google and the forums are your friends!