Applying to graduate school during your senior year in college, or sometime thereafter, is a significant undertaking that will require a serious commitment of time and a particular attention to organization.
Obviously, your application process will be driven by different deadlines depending on the graduate field you have chosen and, even within that field, on which individual graduate schools to which you're applying. Still, there are general application schedules that you should become familiar with, and there is some basic advice that will help you navigate any of these application processes.
Junior year: Getting ready
If you plan to enter grad school the fall after finishing your undergraduate degree, then starting early is the best way to explore the options that graduate school has to offer. Nearly all universities have information at the reference desk of the library about graduate schools and programs. What's more, research your own school's faculty — many of them have likely been graduate students at one time — and feel free to ask for recommendations or personal experiences. If you're having trouble identifying the program you might wish to enter, or even your specific career goals, speak with your faculty adviser or someone at your school's career development office.
When you identify schools and programs that interest you, learn about admission requirements, degree options and curriculum, faculty interests, specialized facilities, and financial aid options.
Taking the required tests
Most programs require that applicants take the Graduate Record Examination (GRE) or another standardized test. Your school's career center should have information about when these tests are given and how to register to take them. Be sure to take the test early enough for your scores to be sent to programs in time for their deadlines.
Senior year: Applying to graduate school
A few graduate schools have a rolling acceptance process, but many have an application deadline, often January 1 for the students hoping to start classes the following fall. Of course — both to greatly improve your odds of being accepted and getting financial aid — you need to meet the deadline. In addition to your GRE test scores, you will need to send undergraduate transcripts, a completed application form, and letters of recommendation.
Most applications require an essay that plays a big role in whether or not you're accepted. Admissions committees use the essay to evaluate your understanding of the field and if your particular interests in the field are a good match for the program's research bent, your writing skills, your motivation for applying to graduate school, and a few other things. Take this essay seriously, and be honest about what interests you in the program. Feel free to include the names of faculty members that you'd like to work with. (If you did your preliminary research thoroughly, you should have a clear understanding of the faculty and their particular interests by now.)
Getting your letters of recommendation
Many graduate programs prefer letters of recommendation from former faculty members who can evaluate your academic and potential research abilities. But programs that emphasize professional practice may ask for letters from employers or supervisors. When asking for letters of recommendation, you should provide the envelope (and pay postage) and give the person plenty of time to complete your letter - at least one month ahead of the deadline. In most cases, once someone has written one letter for you, it's pretty simple to rework it to send to other schools.
Visiting the schools
If you can, visit the schools that interest you either before or after you apply. A personal visit not only allows you to gage how you might fit in at each particular school or program, but at the graduate level a personal visit can impact your chances of being accepted or being offered financial aid. This is because the faculty is much more involved in the acceptance process of graduate students than they are at the undergraduate level. Bring your resume and be prepared to meet faculty and ask questions about the program.
Following up with admissions
Once you have applied to the program(s) you've selected, follow up with each about two weeks before the application deadline to ensure that loose ends or missing pieces can be taken care of. Take nothing for granted. Admissions staffs do an amazing job tracking and documenting the incredible volume of information they deal with each year - but mistakes do occasionally happen. Call the admissions office of each school about ten days after it should have received your information to ensure that the office deems both your application materials and your financial aid materials complete.