How do you take notes?

We all deal with a lot of information. What are your strategies of taking notes for new information?

Do you take any notes on paper? If so do you scan them or otherwise digilatize them?

Do you have specific strategies for deciding which information to write down?

How do you write notes to capture all important information?

Do you tag your notes?

If you use Evernote, or a similar system how private are your notes? Would you allow friends to read in them? Your spouse?