OpenHistoricalMap has several resources for learning about the project, asking and answering questions, and collaboratively discussing and documenting mapping topics.
Community maintained guide for beginners.
Ask a question or look up answers on OSM's question-and-answer site.
Ask a question or discuss interesting matters on the OHM mailing list - sign up at the link above.
Questions and discussions for those that prefer a bulletin board style interface.
Interactive OHM chat on the openhistoricalmap channel, courtesy of OSM-US.
Free-flowing chat about OHM, courtesy of some enthusiastic OHM users.
With an organization making plans for OpenStreetMap? Find what you need to know in the Welcome Mat.
Browse the wiki for in-depth OHM information as well as very helpful OSM information, courtesy of the OSM Wiki.