From those who do things right. would be my answer.
The ones who make mistakes are (hopefully) corrected by the ones who do things right.
The best information comes from those who do it right, and have the patience to take the time to explain in consice detail to others where the mistake occured, or why the mistake exists, and then why it needs to be corrected, how to do it or at least emulate a corrective measure.
Personally, I am interested in not only the clothing, but also the history and the 'whys and wherefores'.
As it is and almost endless ocean of knowledge, it takes a small army of willing souls to adress all of the questions. This is wherein lies the power of this or any other fora. It is always a pleasure for me to learn from others as well as share. Among our finer members, there is also an abiding mutual respect for anothers knowledge, and so in practice, a demonstration of gentlemanliness.
I believe also that finer behaviour should accompany finer clothes. Again, in a social forum, it is always a good opportunity to practice ones ettique. All too often we see a typical thread degrade into a pissing contest and this is not gentlemanly. Thankfully, there are many members here who always give their best effort and seek to boaden their limitations and enrich the forum and all who read along from the outside.