Once you have found a forum or online group that suits you you may find that some individuals want you to start corresponding through private messages or e-mail. However, there's a downside to this, others won't be aware of those conversations and the person you are in contact with may drop out after a while.
Whenever possible/ appropriate, write your thoughts, comments, and questions on the forum. That way you will be corresponding with a whole group of people, you will be more visible and everyone will benefit from any response / feedback.