In general, of course, the academic sphere is arranged in such a way that such a community is usually face-to-face conferences on your topic: after all, for this purpose, narrow specialists from a direction close to you gather, often stars in their fields, who can give advice, suggest literature and etc. Online I would recommend resources such as Google Scholar and Academia.edu, where you can learn about people who are engaged in issues similar to yours, and get advice.
Yes, there is. Welcome to this resource http://www.aspirantura.spb.ru/forum/ A regular forum, but it seemed to me on the topic - the most complete. As usual, everything is categorized by headings. There is a personal and so on. Don't be confused by the SPB domain - an all-Russian forum.