Sending Scores or Improve?

<p>First off, if I took the December SAT, now do I have to send UW my scores if I plan on applying for the winter quarter 2013?
Also, I plan on retaking the test. When is the latest time I can take the test and still send in the scores for my Winter 2013 admission? (I am a senior, by the way)
I got 570 CR, 570 M, 670 W ES 9. This was my first time taking the test. Should I send these scores or should I retake in January or March?
If I plan on retaking the test and improving, which course should I go with?
I've already exhausted my Blue Book... so which prep book is next best?
Kaplan? Princeton Review? Barrons? McGraw Hills?
And if I do retake (shooting for 2000), when should I?
Also, if I improve my scores, do I have to send the old ones to UW?</p>