Pooks, I understand your frustration. I started riding last year and because of an innate desire to "know stuff," (I'm a lawyer; what can I say) I started reading up on lot of cycling-related topics--everything from fit to components to frame materials to wheels. You name it; I've likely done a little research on it. In the course of doing that, I've grown to understand that there are various schools of thought on just about everything in cycling. There may be majority and minority views, but there's rarely one "right answer."
As exhausting as it can sometimes be, all that information has helped me feel more confident in dealing with the folks at the various LBSs that I frequent. Some I've grown to trust more than others. Since there is usually no one answer on any given matter, I tend to distrust the ones who act like there is. I gravitate instead to the ones who are willing to take the time to discuss the pros/cons of something with me or to explain the "why" behind their advice. If they take the attitude with me that you have to know everything about bikes/cyling to know anything, I leave and never return (I have a previous post entitled LBS Rant that describes just such a situation). If they make it clear that I appear to already know more than they do (again, I've had this happen), I steer clear of them too. They're salespeople; nothing more and nothing less.
So, I spend a fair amount of time reading up on something before I buy/go to the LBS. I want to engage with them as intelligently as possible and, for me, that means doing some of my own legwork. Thanks to forums like this, roadbikereview.com and various sites that provide a wealth of information, I find it possible, though time-consuming, to do.
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher