Something really important -I want to get a head start, I intend to apply as early as I can. What thing do you guys highly recommend I should begin doing right now and complete by this month?
Can't help you much on the SAT prep area or how to apply for financial aid
You can find the essay prompts on the website. You'll have to pick one topic and write an essay on it.
For some universities, you will need to write some more essays.
(It can also be done by snail mail I think - but I'm not sure about that whole process)
You will also have to write TOEFL or IELTS if you haven't already. Some schools may waive it's TOEFL requirement due to your high SAT CRW score. Still, it's better to be safe - write it as soon as you can.
In your case, would highly recommend using ED for universities you really want to get into because it shows interest and thereby increases your chances significantly.
CS is one of the most competitive majors.It's hard to get into a top tier university and it becomes really hard if your intended major is CS. I would urge you to apply to a lot of safeties.