If there's one thing you can be sure of after leaving the NICU, it's that you're going to be asking a lot of questions. You'll have questions for the doctors, nurses and hospital staff before you're discharged and will undoubtedly have countless more once you arrive home. In fact, it's not a bad idea to write down some of your non-emergency inquiries and bring them up at your baby's next doctor's appointment.
For all other non-life-threatening questions, try consulting other preemie parents. The Internet is a wonderful tool for this kind of research, as many other people are or have been in your situation, and your question is almost certainly not unique. Dedicated preemie Web sites, support groups and message boards can offer insightful answers and advice for inexperienced preemie parents.
Also, don't let your lack of knowledge stress you. Before you know it, you'll be the expert that parents are seeking for help and advice.