From my experience - even when you are a fairly seasoned professional, it can be pretty hard to figure out if you will like the job you are interviewing for. Probably because, at any point in your career, you're looking to make a change and make some aspect of your job new, different and hopefully better. Any job is such a complex mix of people, organizational culture, rules, technology and business domain mechanics, that it's nearly impossible to get a full picture.
Thinking back to my college days... I'd recommend the following... this is somewhat US biased, as that's my career base, but I have trouble seeing these tricks failing in any technical field.
Use your school's job hunting mechanisms extensively
Organizations that have taken the time, money and energy to recruit at your school, post on job boards and otherwise be on your campus have a vested interest in hiring you. Most companies don't go to this effort if they haven't had a good experience with graduates from your school. It's quite likely that they have experience with graduates from your program of study and they already like what they see.
Which means your chances of being getting a job and being happy at it increase greatly.
It also means they have people on their staff who have some experience trying to answer college grad questions in helpful ways. I scoff at companies who don't send a technical person somewhat related to recruiting areas to the job fairs or interview sessions on campus as there should be someone there who actively manages college grads who can speak to the entry level onboarding process and general career options from a hands on perspective.
Job fairs are a great way to have light weight contact that goes beyond a company's website, where you can clarify the kinds of things you might do starting off. Many companies I've recruited for (as a technical hiring manager) will not commit to a certain position's availablity - our needs are too vast, and the projects are too ever-changing for us to be ready to commit without interviewing. But I am well versed in what most teams are like, the current range of likely projects, and what it'll be like to work for us, regardless of the specific project. You're not likely to get this sort of information from a corporate website, as this is ever changing, complex, hard to communicate stuff that doesn't lend itself well to static content.
Browsing a job fair lets you get a baseline. Searching websites may help you refine that baseline...
The wider world
The range of companies is pretty much infinite. For the most part, a good bet is to have a sense of a few basic company qualities that may fit your basic desires:
Big vs. Small - most big companies have well structured employee intake processes, offer a fairly well-defined job and can give you exposure to more mentoring. Small companies, OTOH, can give you a more broad experience as you do more diverse work when there are fewer people there to do the work... they can also be more chaotic, and less stable with less clear expectations.
Business domain - different areas of the economy tend to have different corporate cultures. In essence, it's a likely conjecture that government defense contractors in any country are more like govt. defense contractors anywhere in the world than they are like small venture capital funded startups anywhere in the world. For the most part, companies compete with each other in a business area, as they often want the same type of people - and it's not necessarily just your degree, it's also your personal style and how you work within a team.
Interal Vs. External - for the most part, there are different demands between roles that face a company's customers vs. roles that come in contact with people only within the company. This can be a lot of different jobs - for example a software developer may develop code for an internal company app used only by the accounting department, or he may be a consultant developing code for a customer who pays the company money. Same job, but vastly different experiences, support structures, and expecatations.
Particular work/life benefits - different businesses but also different corporations will have different benefits in this area. I don't mean the easy to compare paper benefits - like health care, insurance, time off, etc. I mean the quality of life benefits - like private offices vs. cubicles, capability to work from home, investment in tools and technology, the definition of "appropriate personal use" of this equipment, etc. You'll see over time that these offering center around a business domain to some extent, but can still vary markedly. Knowing and thinking seriously about what will work for you is important, and to get this information, you'll likely have to go on an interview.
The name of the game
IMO, the name of the game is to maximize the useful job offers while minimizing the time you spend acquiring them. That means figuring out a collection of places to apply, and then scneduling interview options based on what you feel are the most likely good fits for you. A trick is to balance the hours you spend researching companies with hours spent actually talking to people through either job fairs or the interview process so that you can start to gain insights into the areas that sound most interesting to you.
I tend to treat this as a phased process. I research a collection of jobs, I send out a batch of resumes and coverletters, I wait for follow up. As time goes by, I track the follow up to see what was most interesting to me, and what seemed most likely to yeild a good job offer. Then I repeat targeting those areas that seemed to be the likeliest matches and finding competitors or similar businesses to widen my scope again.