Good questions! I'm glad you are researching these issues with an inquisitive and open mind!

Bitcoin was announced on the public cryptography mailing list about a month before launch, a list that had been around for a decade or longer and reached, directly or indirectly, nearly all the people who (at that time). would have the slightest interest or understanding in an experimental cryptographic currency using digital signatures and hashcash PoW. I've read there were thousands of subscribers. but I don't really know the number, nor do I know if that number is/was public. You can see the original message and subsequent discussion here: https://www.mail-archive.com/cryptography@metzdowd.com/msg09959.html

After the cryptography mailing list, the original venue for discussing the project was the bitcoin mailing list on sourceforge, which started the same month as the launch: http://sourceforge.net/p/bitcoin/mailman/bitcoin-list/?viewmonth=200901

As far as forum posts, satoshi posted about bitcoin on a p2p forum about two months after it launched: http://p2pfoundation.ning.com/forum/topics/bitcoin-open-source

The bitcointalk forum (called the bitcoin.org forum at the time) was created in November, about 9 months later. However, the very first post to that forum references an earlier forum, also on sourceforge (the forum is no longer accessible though). You can read that post here: https://bitcointalk.org/index.php?topic=5.msg28#msg28


None. The project was announced on a public mailing list and code made available to the public before it was launched. All of these announcements and messages are archived and those archives can be read today. According to Greg Maxwell there were quite a few people mining it, at least intermittently, from the very beginning, and a much larger number over the first 6 months to a year (a quote to that effect is on this forum but I don't have a link to it this very moment).