yeah... my senior year was depressing as hell. i REALLY hope you have a better experience. i wouldn't hope anyone my experience.
the sooner you finish those essays the better EVERYTHING will be as the deadlines approach. summer is your best time to do this. don't put them off because commonapp is not up yet or whatever. the essay topics stay the same. just brainstorm and spill your brain onto that page.
sometimes the silliest topics become the best essays. don't even think about the topics. the topics they give you (usually) are so encompassing that almost any type of essays will fit them. it's good to read examples, but don't let it help you procrastinate on actually writing by making you feeling like you're doing actual work. just read a few. more writing, less reading.
i am ranting about essays because my essays that i sent in were terrible. In retrospect, I actually had couple of really good ones, but I ended up sending my crappiest ones in reality because I was so tired (TERRIBLE senioritis, procrastinated BADLY), and couldn't give myself a rest to develop a fresh eye before i had to sent the apps in.
seriously. essays are what it all comes down to, especially if you're applying to those top-tier colleges. because everyone has impressive scores and extracurriculars. it's actually not too late to start some kind of volunteering either. i started SAT-tutoring in my senior year and put that on my resume.
and yes, a resumes will be EXTREMELY useful. you should compile one before the essays, even.
oh and even if you think you are set on a college, research other matches that suit your needs.
if you can pick your senior courses, take some classes that you actually want to take instead of taking classes you think the adcoms want to see.
i guess a lot of this might not be applicable to you because i'm basically advising my younger, rising senior-self. but maybe it'll be helpful to others. ;___;