The DMC offers many different tools for making requests because our user community is so diverse. We've assembled a list of tools organized by the type of data available, the way the tool works (eg. browse, search, etc.), and other information. You can find this list here.
It may also help to review our data overview page, which outlines the types of data offered by the DMC and provides links to some commonly used tools.
If all else fails, submit your question to firstname.lastname@example.org.