Not so much a rule or guideline, but a request...
Remember, we were all new members at some point in the history of the this forum. We want to be welcoming to our new members and make sure they feel comfortable becoming a part of our community. When I see a thread from a new member introducing himself read 120+ times and I'm the only one to post a "welcome to the forum" it's a little disappointing.
So, please take 30 seconds and post a welcome to our new members.
Thanks,
Shane