The first step is to do a little research. You need to take the time to look at all the directions your corporate library career could be taking. People in corporate library positions work in many different fields, including medicine, law, IT, data mining, knowledge management, education, and many more. A little time spent online in forums and blogs targeted to librarians can help you see how individual people see those jobs and how their day to day work goes. Remember - everyone is going to experience the same job a little bit differently.
Once you've got a good idea what a job as a corporate librarian is like, it's time to take a look at programs. Check out degree programs that offer local and distance learning opportunities. Just make sure that you'll be applying at an accredited one. Remember that to be a corporate librarian you're likely to need a minimum of a master's degree in library and information science. The program you enroll in needs to have accreditation from the ALA or American Library Association. Check out colleges and universities that offer the degrees you've been looking for and don't be afraid to ask questions.
Take the time to read feedback from other students in the library science field. They can tell you how good the program is, your chances of employment after graduating from it, and lots more. Check out online forums and blogs for library students and don't forget to schedule visits to schools you're interested in. If you already have a bachelor's degree, you may be able to move right to earning your master's degree. Remember to take advantage of all scholarships and other financial aid options for prospective librarians. They can greatly help in getting the schooling you need for this kind of position. Remember to take coursework in the special areas that are most likely to get you the job you want.
After graduation, join professional associations that will help you. The ALA and SLA (Special Libraries Association) can be a big help. You don't have to wait until you're out of school, either. Their resources can help you while you're still in your graduate program. Be sure to get as much related education and experience as you can. You can never have too many qualifications in this field. Be sure that your resume and cover letters are all carefully written, concise, and to the point. If you're someone who deals in information, it's going to be considered very important for you to be able to disseminate it well. A well organized, well written resume can be the way you show this ability.
Be sure to mention all professional organizations you're involved in, as well as publication, special awards and any other important factors that might be important to your new job. Choose the positions you apply for carefully - in the professional field, a shotgun approach isn't going to be looked on well. Be sure that you get guidance from academic advisors and professors as well as anyone else you may have networked with. Many people get help finding their first corporate library job. The right contacts can make the process a lot easier.
Once hired, be sure to keep up your education and professional memberships. Learning doesn't stop when you get your first job! Take the time to learn everything you can about current trends and technologies so you stay competitive.