(MONEY Magazine) – For college-bound youngsters and their families, an aptitude for meeting deadlines is the first college entrance requirement. Failure to file the right form at the right time could hurt your chances of attending your favorite school or getting financial aid. ''Establishing a timetable is very important,'' says Sanford B. Bing, director of Princeton Educational Resources, a tutoring, counseling and testing firm in Princeton, N.J. ''Time can pass quickly, especially as a student begins his senior year and tries to juggle applications, academic pressure, extracurriculars and a social life.'' Here are guidelines for high school students embarking on the college application process:

High school sophomore year October: As a tenth-grader, you may want to take the P-ACT+. In part a practice version of the ACT entrance exam that you may take in your junior or senior year, it can give you an assessment of your academic skills. It also includes a questionnaire meant to provide you with guidance on study habits and career choices. At this point, you can also take the Preliminary Scholastic Aptitude Test, which is a shorter version of the SAT, the other big admissions exam. You shouldn't feel obligated to take either ''P'' test. But if you do take one, don't fret over the results, which are not passed along to colleges.

High school junior year September: Register for the PSAT, given in October, even if you took it in your sophomore year. Again, the results won't be sent to colleges, but juniors who are among the top scorers in each state may be considered for National Merit Scholarships of up to $2,000. National College Fairs, at which representatives of 130 to 440 colleges hand out information and answer questions, start to open. The fairs are held in 25 cities at various times of the year.

November: High schools start to hold college and financial aid nights to brief families on the application process and sources of financial aid.

December: This is when you will receive your PSAT scores. Make an appointment with your guidance counselor and, using the scores as one factor, discuss the type of school you might want to attend. Check the schedules to determine when you will take the ACTs or SATs and the achievement tests, which measure knowledge in specific areas. The exams are given at regular intervals during the school year; you must register about six weeks before the exam date. Results will be sent to the colleges you designate.

January to March: After consulting your guidance counselor, college catalogues, reference books and computer data bases -- which are available in most high school career centers -- you can begin to develop your preliminary list of about 20 colleges that seem interesting to you.

Spring break: Try to make informal visits to a few nearby schools to get a feel for the differences between large and small campuses, rural and urban and the like. It can be helpful to talk to college students who are home on vacation.

May: Advanced placement tests, which award college credits to high scorers, are given.

June: Request college viewbooks, catalogues and application forms. Examine the material and refine your list to 10 or fewer schools.

Summer vacation: Begin to schedule interviews and campus visits for August, September and October. Start thinking about your application essay.

High school senior year

September: Work with your guidance counselor to narrow your list to five to eight final selections. Ask teachers to write the recommendations that accompany your applications. Work on your essay so you can show it to parents and teachers in time to make revisions. If you are applying under any Early Decision or Early Action plans, make sure your transcript is correct and ready to go out.

October: Start sending applications to schools with rolling admissions. Finish up your Early Decision or Early Action applications, which are due between Nov. 1 and Dec. 1; some schools require early financial aid forms with those applications.

December: Many high schools require that you submit regular-deadline college applications for processing early this month. Pick up financial aid or application forms from your guidance office. Brace yourself: Early Action and Early Decision responses will arrive from about Dec. 15 through Dec. 31.

January: Final deadline season begins. Almost all schools require regular admissions applications by one of these dates: Jan. 1, Jan. 15, Feb. 1, Feb. 15 or March 1. File financial aid forms. Have your high school records office send transcripts of your first-semester grades to the colleges to which you have already applied.

March and April: Go to the movies. Walk in the woods. Take cold showers. Casually check the mail. Remind yourself that there's no such thing as the ''one'' right college for you. Think of all the successful people who never even went to college. Take a deep breath. Now open the envelopes and read the decision letters. Good luck!

The article on these pages is adapted from MONEY Guide: America's Best College Buys. This special MONEY Guide offers advice on paying for college and key data on 1,000 schools, in addition to identifying the 200 schools with the best education for the dollar. It is available on newsstands for $3.95 or by mail for $4.50 from MONEY Guide: America's Best College Buys, P.O. Box 30626, Tampa, Fla. 33630-0626.