My Five Basic Working Rules in Healthcare IT (v1.5):
(1) First, do no harm. Healthcare is a mess. If you can't fix any problem, at the very least don't add to them.
(2) Study and fix processes first, automate later.
(3) When implementing any system, ask what is the VALUE to the patient or clinician. If there's none, don't waste your time!
(4) Clinicians often don't know what they want. Illustrate, elaborate, test, build prototypes. Never assume.
(5) If all else fails, remember rule no. 1