You should start applying in the fall of your Senior year. You should aim for September and October because you will be able to qualify for the most amount of financial aid that way and if the school has "early action", you will be guaranteed to get the school's decision back usually before Winter Break.

 Google "Apply" and then the school you want to apply to. This will take you to their application.

Make sure you have your social security number so they can connect your college application with your financial aid application!

The application can be a breeze (15 minutes tops) or it can be more in-depth (with essays, etc.).

Don't let essays discourage you- one essay could get you into the school of your dreams.

Essays should be typed out on a separate document like Microsoft Word (so it can catch grammar mistakes) and then proof-read by your English teacher or college adviser. Taking this step will ensure that your essay is the best is can be and will give you a better chance at getting accepted to the school.

Request your transcript to be sent to the school through Parchment.

Instructions on how to request your transcripts can be found here 

Request that your official SAT scores be send directly from SAT to each college.

You may have already listed certain colleges when you took the SAT. Check the report they sent you to see where your scores were sent.

Instructions on how to request SAT scores be sent to colleges can be found here.

Note: DO NOT PAY THE FEE FOR SENDING SCORES- Your college adviser can supply you with a fee waiver.

Check with each college to see if your application is complete.

Call the admissions office and ask "is my application file complete?"

They can then inform you if you have any missing documents of if you have everything turned in.