College applications can be very stressful if you're not prepared, organized, and knowledgeable for what you're supposed to be doing. Know the important dates like early decision (your school will probably tell you when these are) so that you can find a schedule that works for you.
Most applications are fairly simple - type or write out your name, address...all that good stuff. The most time-consuming portion for most students are the essays. Essays won't make or break your app, but it's important that you make it a quality piece of work. Luckily, the questions are about you, which makes the prompts fairly easy. I had come across some questions that weren't about me, but most of the time, unlike essays that you see in school, you are prompted for your opinion. Of course, you'll need much thought and, in some cases, imagination, but if you don't leave your essay to the last minute, it should be fairly simple to complete.
Most apps also have a page or two that request notable achievements you have been honored with, volunteer experience, work experience, etc. This is where students get to shine. The more "stuff" you have done, the more interested the person reading your app will be. Try to remember everything that you have done during high school and let the college know what you've done. Remember, everything counts. Music lessons (or even playing an instrument without a school band affiliation) count. Sports count...I could go on, but you get the point.
Over the summer, you should be focusing on pinpointing the colleges that you want to get into. The amount that you should have in mind is a subject of debate with many people, but it's good to know what you're capable of handling. Applications cost money (usually), so if you're not in a position to throw out apps left and right, be sure to analyze your options carefully. Say you want to apply to 10 colleges (which many students would consider a lot). What I would do if I were applying to 10 would be: 2-3 low probability school, 4-5 fair probability, and 2-3 high probability. The fair probability schools are what you're most likely going to get into (and generally your favorite schools), but you should still be aiming for the low probability schools. I forget the terminology that schools like to use, but you get the point.
Once you've settled on some schools, see if you can visit them. I was one of those students that thought it was useless to go see the school, but I ended up enjoying the visits. People don't rent out apartments before seeing what it's like. College is the same thing. Sure, you could have chosen a great school for your prospective major, but if you don't like the atmosphere, then there's a problem (which is why visiting is a good idea).
During school, you'll want to talk with teachers, coaches, or anyone who can give you a letter of rec. Some schools want several...others don't want to touch them. This is why you need to be organized about your school decisions. The earlier you sit down and talk with your teacher or counselor, the better. By October, most teachers will be very busy with letters of recommendation. There will most likely be some sort of waiting list, so it's better that you get your letter early. If you have any schools that use the Common App, knock that off your list first via the website. Schools have a certain date that they open registration, so if you can knock them off the first day that they open, all you have left are your essays. Remember, the earlier, the better.
If your school requires SAT I's or SAT II's, register for however many you need. You can also take more ACT's if you wish, and it's not a bad idea if you want a chance at a higher score. In terms of grades, keep doing as you were the past 3 years of high school. Colleges don't want to see your grades slipping, so try not to let Senioritis get to you.
By early spring, you should have a response from your colleges (it could be around January if you submitted early) if you applied in the winter. Contemplate your choices and make a decision with your parents. You may have to wait until late spring for some of your responses, so make note of your deadlines.
Senior year is a great school year, and probably the most fun out of all your time in high school. Make sure to enjoy it, and good luck!
