There is a new resource for help in town for wordpress.com users. http://faq.wordpress.com. Run by the brilliant minds behind WordPressMU and wordpress.com, this FAQ offers frequently asked questions to help you understand how wordpress.com works and what you can, and can’t, do.
Recent answers to frequently asked questions about wordpress.com include How do I send out update pings, what is free and what is going to cost money, can I edit my templates, and how do I change the title of my blog.
To ask a question, either post a comment or use the Feedback button in the WordPress administration panels to send a note to the developers with your question.