About r/comiccollecting (Reddit)
For newer collectors, the community is one of the better free educational resources online — recurring threads cover the basics of grading scales, the differences between the major third-party graders, when (and when not) to slab a book, how to spot restoration and trimming, and how to evaluate raw books for grade potential. More experienced collectors use the subreddit for second opinions on grade calls, market-trend discussion, and convention reporting.
The community moderation is active and the rules around buying, selling, and trading are strict (most direct transactions are routed to dedicated marketplace subreddits) — which keeps the main feed focused on discussion rather than commerce.
The subreddit is free to read; account-free browsing is supported but participation requires a Reddit account.