I just Beat The GMAT!

I decided to get the Princeton Review online prep course (GMAT Online- the self-guided one) last month and scheduled my GMAT for a month later (today). I massively underestimated how much time I would need to prepare for the test and, while I got through a majority of this program and a good portion of the red book (Official Guide, 12th edit.) I still felt extremely nervous and unprepared this morning.

Of the two complete GMAT practice tests I took, I achieved scores of 560 (36V 31Q) and 570 (36V 33Q) and on the individual quant practice section I scored a 37. So through these PR practice tests my verbal was consistent but my quant ranged from 31 to 37.

I took my GMAT this morning and got a 550 (36V [surprise, surprise] and 30Q). Obviously there is a ton of room for improvement. My dream school is University of Washington and I'm going to give myself until R1 next year to improve my score. But that actually just means I will have to take it again before June of 2012. I am looking to take it again in April and I feel that should be enough time to learn enough to bring my scores to a higher level. The GMAT score I'm looking for is 650+. My GPA is strong, as is my extra-curricular and (I feel, although short) my employment history.

Age: 24
GPA: 3.5
Relevant Employment History(almost three years including internships): Marketing internship at a large frozen snack food company, supervisor at large food/event service provider for sporting events, worked with a best-selling author/business consultant (assisted in developing/conducting interviews and compiling data for a recently published book on customer experience, worked as a project manager with this company), worked in a call center for a mutual fund company where my position was outsourced to another company, was asked to go to that company with a promotion, stayed at that company for a short period of time and I am currently working as a supervisor at Starbucks.

My question would be if anyone else has been in this position- what did you do to improve? I consider myself a quick learner and don't think it will be difficult to bring my Q score up, which is good for me because I have a long way to go up. I signed up for the 60 day Beat the GMAT emails. I don't think I can afford any more pay programs but if anyone has any free resources or minimal cost resources that greatly helped their quant score, I would appreciate it.

Thanks for your help,
Ryan