I did a Google search this morning for "write like J K Rowling" and an interesting article from TheCuckleburr.com popped up.
J K Rowling went from barely getting by, to living a life on easy street, but as Suzanne Harrison explains in her article titled Are You the Next J K Rowling?, it definitely wasn't "easy".
I have not read the Harry Potter books and don't plan to. It's just not my "thing", but I cannot fault the success of the series. It's almost a culture unto itself.
Five years of outlining and preparation prior to starting to write the first book were definitely worth it -- and Ms. Rowling has the bank account to prove it.