Your best bet is to find people with first-hand experience, who understand the science behind the concepts they are discussing and can offer all of this rather than just opinions.
Everyone has an opinion – some people think the Earth is flat for example – but in audio and other areas, there are facts, answers and genuinely useful advice, derived from science and first-hand experience. This is what you want to seek out.
Customers often say “I read in a forum that I should buy this but then someone else said I should buy that…”. There are some great, well-moderated forums and then there are others are filled with subjective, conflicting, technically incorrect misinformation, speculation and ‘noise’, written by people often with no actual experience or technical understanding of what they are talking about. Even good forums experience this noise and readers often lack the knowledge necessary to effectively filter out the genuinely useful information.
You should be sceptical of so-called experts who spend hours every day in forums. It indicates mainly that forum writing is their area of expertise, rather than servicing and setting up turntables for example! I can say that most real experts won’t be found arguing online. They are instead probably focussed on their work, gaining even more experience whilst others discuss their opinions! These are the people you want to seek out.