Choosing the right graduate school is a difficult and time-consuming task. It is also a very personal one--there is no such thing as an all-purpose, one-size-fits-all graduate school. So don't run off and enroll at the first school that has a program in your field. Take the time to figure out what kind of school is best for you. I guarantee you will be glad you did.
A good place to start your search is in a large general catalog like Peterson's Guide to Graduate Programs. You won't stay here long, so you don't need to buy the book; just truck on down to the nearest library or career center and read their copy.
Once you get into the catalog the first thing you'll notice is that there are a lot of graduate schools. They range in size from the Brobdingian Ohio State to the Lilliputian Caltech. They are in every city, state, and nation. And they offer every imaginable program. So, how on Earth will you be able to find the sharpest needles in this enormous haystack of possibilities?
First, put down the book. Then pick up paper and a pencil. Write down all the things you want in a graduate school. East coast, west coast, or somewhere in the middle? City, small town, or rural? Large state school or small private university? Astronomy or zoology? Your list will guide you to the right schools. When I was trying to choose a graduate school, for example, I decided that I wanted to study astrophysics at a medium to large school in a city near the northeastern seaboard.
Now pick up the catalog again. Scan through all the entries and reject every school that doesn't meet your criteria. It sounds like a lot of work, but really it isn't. (When I did this exercise, I didn't even have to look at entries in forty of the fifty states because they weren't on the East Coast). Even if your criteria are very different from mine, the principle is the same. By applying progressively more specific selection criteria to each university, you can gradually whittle down the possibilities. At this point in the process, you should be aiming for about a dozen potential schools.
After you have put together this preliminary list, show it to faculty members and fellow students. Ask them for their opinions of the various schools. Are there any that they would add to your list? Any they would definitely subtract? Consider their arguments and then adjust your list accordingly. But never make a change that you don't like just because someone tells you to. After all, you are the one who will have to spend the next several years at that school.
Most grad school hopefuls stop their search right here. List in hand, they'll simply copy down the schools' addresses or URLs, request application materials, and apply.
This is a bad idea for two reasons. First, the entries in catalogs are at best dry statistics and, at worst, shameless advertising; they're impossible to use to discriminate between competing programs. Second, the more you know about the school--and the more the school knows about you--the better your chances of getting accepted. So go ahead and write down the names and URLs of the interesting schools, but hold off on filling out your applications. You need to go surfing first.
As far as I know, every graduate school has a Web site. The vast majority of these are rich sources of information for prospective students. They have links to downloadable application forms, photos of the campus, lists of all the graduate programs and courses, individual department Web pages, profiles of affiliated research centers, and the CVs and biographies of virtually every faculty member. An afternoon spent scanning home pages can turn up valuable clues in your search for the perfect school. Take my graduate school, the Johns Hopkins University . The faculty list on the physics Web page  contains a number of respected astronomers and astrophysicists. That's good, but many other physics programs have similar rosters. Probing a little deeper into the departmental Web site, however, turns up gold--the Space Telescope Science Institute , and all of its hundreds of resident and visiting astronomers, is right across the street!
Although scanning Web pages can help you develop a pretty good mental picture of each of your prospective graduate schools, you're unlikely to find the answers to many important questions. What projects are current grad students working on? Do grad students get to use all the facilities mentioned on the Web? What are my chances of being accepted? The only way to find answers to these kinds of questions is to talk to people. More specifically, faculty members, graduate students, and postdocs in your field at the universities that interest you. But how can you reach these people? Once again, the Web comes to your rescue.
People in Your Neighborhood: Graduate Students
It may seem peculiar to introduce prospective graduate students to graduate students, but keep in mind that you aren't a graduate student yet. And if you do become one, most of your neighbors will be fellow students. So getting to know a few "real" grad students is an important step in the application process. Suppose you were buying a new suit. You wouldn't put down the cash (or plastic) until you had tried it on, would you? The same principle applies to graduate school. By talking with a few current students and imagining yourself doing what they're doing, you can try graduate school on for size. E-mail also works, but not as well. You can learn a lot from the tone of a student's voice and the spark in (or dark circles under) their eyes.
Don't be shy about asking anything you want to know. Most grad students--bitter, sleep-deprived, or just plain frank--will be generous with their answers. And if you ask the right questions, they'll let all the departmental secrets out of the bag. So ask away ...What percentage of the new students survive the first year? How long does it really take to graduate? Where do recent graduates work? Which professors have all the funding? Who is the nastiest advisor? And who is the best? Which one stopped doing research 20 years ago but still comes to colloquia for the donuts? Who drives that swanky new Mercedes parked out front? And knowing what you now know, would you enroll here again?
University home pages all have extensive online directories. Type in the name of a faculty member, and the directory spits back their address, phone number, and e-mail. It is that easy. Finding graduate students and postdocs is only slightly more complicated. To get a department-wide sample, start at the department home page and look for a list. These are usually found under a button called "People," or some obvious variation of that. To get the dirt on a particular professor, start at his/her home page and scan for names of underlings and advisees. If there aren't any, you already have one clue about this prospective advisor's personality.
But don't abuse this wonderful resource. Don't send off 100 e-mails all asking "Hey, tell me about your school." And don't pester profs with phone calls. Instead, take the time to prepare a concise letter that tells each person exactly who you are, why you are writing, and what you want to know. If you have a resume, attach it. And before you send anything by either snail mail or e-mail, have a friendly local faculty member read over the letter. Then revise, send, and wait for the info to start flooding in.
The last step before actually submitting an application--visiting your top selections--is optional. But if you can scrounge up the time and money to go to at least a couple of schools, do it. There is no better way to judge the environment of a graduate department or to make yourself known to the faculty members who will ultimately select the incoming class. And before you go, e-mail several department members to let them know you are coming and that you would like to meet with them. Schedule appointments with as many as possible. Make sure that the department chair, the leaders of any interesting research groups, and a few graduate students are on that list. They will be as curious about you as you are about them.
That's it for data gathering. ...With all this information in hand, you should have no trouble crafting some stellar applications and getting accepted by one or more of your top picks. But you still have one major question left to answer before you pack your bags and head off to campus. How the bloody hell and I going to pay for all this?