How to improve your test scores in general
Ok, I am really obsessive-compulsive about scores, so maybe I can help. I certainly wish you luck!
To study for the SAT, I signed up for a Kaplan course. It's pricey but it was worth it to me because they tell you a lot of ways to move faster and not get bogged down on the confusing elements (especially in english) of what are actually easy questions. They gave me a huge coursebook as well as online homework. DO it. All of it. Whether it's assigned or not.
I also went out and bought the blue book (I think it's called the official SAT study guide or something) off the internet. It's really big, and it's really blue, and it's published by the college board, so maybe you can find its ISBN while looking around the college board site. I read through it obsessively and did all the practice tests.
Honestly, the most helpful thing you can do is practice, since you don't have that far to jump. I ended up doing 20 practice tests (and I'm still doing them!), and that's helped me jump about 200 to 300 points in each section. It's a HUGE time commitment, but if you do one every day on the weekends from now until december, you'll be fine.
The other thing you can do to save time is to only do a couple sections from the SAT at a time. It won't build your focus (the issue for me was always staying focused after two solid hours of boring testing) but it will help you all the same and it's a little easier to manage the time.
Prep books, like Khanacademy (I've never used that one), Barron's, Princeton Review, whatever, are all very useful. Basically, you just need to practice the skills. All of the review books will tell you the same strategies with minor differences, but hearing things in different ways will help them to stick. DEFINITELY buy them on Amazon, not in Barnes and Noble or wherever because they can get pricey if you buy a ton (like I did).
I know. It's a huge time commitment. But if I can do it, you can do it, because if you want to go to WP that means already that you're a very determined person. As a side note, I don't think your congressman is the one to whom the test scores matter most, I think that's the WP admissions board proper who look at them. I'm not sure though. Maybe an admissions officer around here somewhere can tell you. Honestly, you don't have that far to go. I don't know how much you've already practiced, but a 100 points is about 5 more questions per section.
I really don't know anything about the ACT, but you can definitely raise your scores to be INCREDIBLY competitive, no matter what area you're from. I'm from CA, in district 7 with DeSaulnier, which is pretty competitive too. However, with effort, I raised my scores to 2200, which is pretty competitive anywhere. I started out with an 1850. Just make SAT prep a part of your life (bring around vocab flashcards, etc) and your scores will go so high. I assume you're busy but it really doesn't take that much time if you can fit 20 minutes of prep in here and there and do tests on Friday night or something. Ok, I talked WAY too much, I just get really excited about the SAT. Good luck again! You CAN do it!