If you haven't already done so log in or create an account—see How to contribute for details of how to do this. Click on the Discussion and Suggestions link in the page header.
Click on the Ask a Question button and ask your question
Your new question shows up at the top of the selected category. Other users can then vote, at the top of the page or respond, at the bottom of the page, to the question.
If you think your question falls outside the current selection of categories you can suggest a new category by emailing the site admins or by adding a discussion / asking a question in the "Research Data Network website features" area.
Note: you will need to be logged in in order to comment upon or vote for an existing thread.