As I touched on above, each college has its own essay requirements, so you'll need to go through and determine what exactly you need to submit for each school.
You'll need to look up the essay requirements for each college—what's required should be clear on the application itself, or you can look under the "how to apply" section of the school's website.
Once you've determined the requirements for each school, I recommend making yourself a chart with the school name, word limit, and application deadline on one side and the prompt or prompts you need to respond to on the other.
The brainstorming you do for the long essay may help you come up with ideas you like for the shorter ones as well.
Also consider whether some of the prompts are similar enough that you could submit the same essay to multiple schools.
Watch out, though, because some schools have a dedicated "Writing Supplement" section, while others (even those that want a full essay) will put their prompts in the "Questions" section.
It gets trickier if you're applying to any schools that aren't on the Common App.
Having this information allows you to plan the best approach to each essay and helps you cut down on work by determining whether you can use an essay for more than one prompt.
Writing good college essays involves a lot of work: you need dozens of hours to get just one personal statement properly polished, and that's before you even start to consider any supplemental essays.
That way you'll be able to see exactly what you need to do and when you need to do it by.
If you have one essay that's due earlier than the others, start there.