Boosting my score and Some tips For critical reading.

[Guidolombardo]

Hello I am new to this forum.
I am not an native English Speaker. In fact, English is my second language. Even though I think i can write and talk considerably well, I'm having problems with the SAT specially in the Critical Reading Section.
I took this test in March, and i did not prepare at all...
My scores where the following:

Critical Reading: 490
Math: 640
Writing: 490

Since then, I've been preparing for the test that is taking place on June 5th, this weekend.
I bought two books: The official SAT college board book, with 10 practice tests and the Princeton Review one...

I took all the tests I could from these books and in everyone my scores ranged like this:

CR: 500-560
Math: 690-770
Writing:500-540 (considering that my essay could have a grade of 7)

I am completely familiar with this math section, and the writing is a matter of more practice for me... But how can i improve my CR section?

I don't have problems with understanding the passages, but with the TIMING, i dont know whether is better to read the passage first, reading and answer chronologicaly, or go to the questions, and skim the passage to answer them.

Someone can tell me some techniques that you have used?

Thank you a lot.