Daily Mail's a perfectly good source. I've noted only a very few times when facts were wrong - reporting errors mainly, and corrected in subsequent editions of their internet product. Indeed, other MSM sources make as many initial reporting errors. Much of the Mail's reporting is garnered from U.S. sources - not only AP but also local MSM and, as you say, they have it up before most anyone, certainly better at it than CNN, which has become a joke, regularly listing Mail stories two days later even though they've taken place in America. While the Mail is in fact a tabloid, it's one that has been around for over a century, first as a broadsheet and then in the 1970s changing format.
Sources to avoid are from those whose writers make their $$$ per page hit: Examiner, Gather, IBT, American Journal. These feature amateur writing and almost no independent reporting.