CGTalk Painter Forum: CGSociety's Painter Forum is fairly active and part of a much greater digital art community. Look at the sticky for "Attention! Look in here before posting a question" for Pixlart's Tutorials and other tutorial links.
ConceptArt.org Painter Forum: Chat with other Painter users for support and general aid.
Painter Forum: TalkGraphics.com forum for Painter users. Information and tips.
Renderosity Painter Forum: Renderosity is primarily a Poser community, but has a Painter forum to discuss the program
Yahoo Group: Painter World: An online forum and mailing list dedicated to the users of Painter.
Yahoo Group: Painter-Novitiate: This is a list for people who are climbing the learning curve Painter 6.
Yahoo Group: Painter_Artistry: Trade digital tidbits with other Painterly purveyors of pixel paintings. Moderator is Karen Sperling, who has been writing about and teaching Painter longer than anyone.