The following rules are quoted from memory. I had to learn them for my Computing course. They were given to us in notes that had been photocopied from elsewhere. I think they're generally considered public domain. If I discover who invented them, I'll attribute them appropriately.
Once upon a time, this node was softlinked to completely insane programming teacher, which wasn't far from the truth.
These are the three golden rules of user interface design. They should help to make software user interfaces easier to use. For each rule, there are a number of principles that help to define the rule. Each principle has a keyword that can help to jog the memory.
1. Place Users in Control
2. Reduce User's Memory Load
3. Make the Interface Consistent