Khan Academy is perhaps the best free education online program. It offers top-quality lectures and tutorials on a number of subjects, particularly math and the sciences. Mr. Salman Khan is a Bengali American who worked as a teacher and hedge fund analyst and one day, after tutoring his cousin for a while, he realized there is value in creating an online tutoring platform so more people can benefit from additional tutoring.
Take time and watch his videos on college preparation. Here is the one on writing a good college application essay.
Also see the video on avoiding common application essays mistakes.
Here is a brief, fun and quite useful video on the topic.
And one more from an admissions officer from Columbia University.
As always, don’t over research – sit down and write your first draft.