The following is a list of rubber stamping/scrapbooking message boards that I have found to be very helpful. Registration may be required to have access to all areas of some message boards.
Splitcoaststampers: this is an active message board with several different fora on subjects such as general stamping talk, scrapbooking, and publication calls to name a few. Be sure to check out the member galleries and tutorials for inspiration and instruction on stamping techniques.
The Stamp Shack: This is a friendly message board for rubber stamp enthusiasts. The Stamp Shack has several fora on topics such as Hall of Fame (for published stampers and stampers who have made stamp company design teams), upcoming events, the Stamping Room (general stamping discussion), etc. The Stamp Shack emphasizes rubber stamping, therefore it does not allow posting of traditional scrapbook pages. Registration is required to post comments and to access the galleries.
Scrapbook.com Forum: This message board is part of the Scrapbook.com website, which is a huge online scrapbooking store. The emphasis here is on scrapbooking, but there is an active stamping and greeting card forum. Access to some parts of the message board is limited to registered members.
Two Peas in a Bucket Message Board: An excellent message board with separate fora for scrapbookers and stampers. This board is mostly about scrapbooking, but there is an active stamping forum. The video tutorials at Two Peas in a Bucket are excellent.
Scrapbook Heaven: As the name suggests, this message board is heaven for scrapbookers. There is a stamping forum, but it is not active.
Rubber Stamp Chat: A message board about all things related to stamping, including greeting cards, Artist Trading Cards (ATCs), tutorials, and swaps.
That is a sampling of the many rubber stamping and scrapbooking message boards on the Internet. If readers find other similar message boards, please let me know.