Educate them about the importance of security, the means of choosing good passwords, and the ways crackers can obtain passwords.

Instruct your users to e-mail copies of their passwords to themselves on other systems

so that they're readily available in case of an emergency

Enforce password change rules but don't tell users how crackers obtain passwords since you could be educating a future cracker.

Give some of your users copies of the encrypted database file as backup in case a cracker breaks in and corrupts the original.