1) there are many options for working in research--you don't necessarily have to work for a pharmaceutical company. The major areas that hire research nurses are universities, hospitals (free-standing and university-affiliated), privately owned research facilities known as "CROs" (contract research organizations), and pharmaceutical companies such as Amgen, Bayer, GlaxoSmithKline, Medtronic, etc.. Look around in your area to see what you have nearby.
2) Qualifications: knowledge of research design and ethics (especially ethics!) is really key as a specific qualification for research. If you have a community college or an online educational option, look for courses in these areas. I think that knowledge in ethics/good clinical practices is the first thing you have to understand. Also, if you know that the potential employer specializes in certain diseases/devices/treatments, be able to show that you know something about their specialty. More general skills such as attention to minute details and a tendency toward perfectionism are also important. With a background in ICU, you will be EXTREMELY attractive to employers, so you should definitely emphasize this. Particularly if you want to work in Phase One trials (these are trials of medications that are being used in humans for the very first time), you will find ICU experience will get you in the door.
3) Areas of research: depends heavily on your interests. If you want to run trials on a variety of subjects and diseases, you should look for a place that has that kind of variety available (i.e., big teaching hospital, university department, etc., but probably not a private CRO or a pharmaceutical company).
4) At interview: you will be asked about how clinical research is different from standard bedside care. And how it is similar! Example: Things that are different: in a research study, you have a protocol you are expected to follow. If you're wondering whether to give a certain medication or not, you must check the protocol. At the same time, if it's an emergent situation, you are expected to use your judgment and NOT follow the protocol if doing so would harm the patient. The protocol is never a substitute for your best judgment! This kind of thing is referred to as "GCP" (Good Clinical Practices)--look up some resources and familiarize yourself with GCP before any interview. GCP, to me, really means that my research patients and my non-research patients all get the same care in terms of quality--I think carefully about what is best for them at all times. You'll also want to spend some time thinking about how to answer questions about your approach to informed consent--this is VERY important and you want to show you've thought about why this is important. I suggest reading the label of a bottle of OTC medication and thinking about how you would talk with someone who wasn't sure about taking it--the language is pretty similar to how a lot of consent forms are written, and it (understandably) freaks out a lot of patients. Bear in mind that your job is NOT to get the person to take the medication--your job is to answer their questions and let them make a decision.
5) You want to look for "research nurse", "clinical research coordinator", "clinical research nurse", and possibly "research coordinator" first. I don't think you should spend time looking for "CRA" (clinical research associate) positions, which are meant for people who have already spent a few years as study nurses and coordinators.
6) Finally, what will you DO as a research RN? This is also heavily dependent on where you work. I have worked in positions where I did EKGs, blood draws, IV starts, and monitoring of infusions, along with all the data entry and paperwork. And I have also worked in positions where I'm more of a paperwork jockey--combination medical detective and data management person. It is really important that you ask about this at interview--find out how you would be spending an average day, because it is REALLY variable. What you can count on is that you'll be working with patients and physicians who depend on you to know your studies well, and that you'll have monitors who will make sure you are doing everything that needs to be done.
Kind of a long answer, but you asked!