Lifehacker has a nice post on note-taking methods.
A few additions:
What you take notes with can make all the difference. Whether it’s a fountain pen, software, or a pencil, experiment but go with what makes you take notes, not necessarily what’s cool.
Remember that the process of note taking has as much value as reading the notes later. In fact, for me, it’s more so. I have numerous notebooks from work that are filled with notes that were never referenced. Just taking them kept me engaged sufficiently to be successful.
Be careful with recording. It’s just so easy to hit the record button instead of taking notes, but be sure you have both the time and the personality type to make use of the recordings. For me, nothing, but nothing cures insomnia faster than a recorded lecture, and I barely have time for meetings or classes let alone twice the time – once for recording, once for review.
My last piece of advice is to never forget that you often have a choice in instructors (in a university setting, anyway), and if you find yourself struggling to take decent notes during class it may be a sign that you need a different teacher. I’ve had some that hopped around so much it was impossible to keep up or make sensible notes of what they were trying to cover, and invariably that translated to frustration in doing assignments & exams later. School’s hard & expensive enough without begging for extra trouble, and don’t be afraid to shift your schedule to get better instructors.