<p>I boosted my writing score from a 580 to a 700 with the help of Kaplan Writing Workbook and Baron Writing Workbook. However, Sparknotes’ FREE guide is just as helpful, it just doesn’t have the same number of practice questions. Another note pretty much anything not made my the college board is going to have inaccurate questions, so make each and everyone of the BB questions count!</p>
<p>edit:
I forgot to mention all the really amazing guides on CC, which are all linked in a sticky thread.</p>