OpenStreetMap 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 a wide range of topical or regional mailing lists.
Questions and discussions for those that prefer a bulletin board style interface.
Interactive chat in many different languages and on many topics.
Help for companies and organisations switching to OpenStreetMap based maps and other services.
Browse the wiki for in-depth OSM documentation.