>Sooner or later, you will meet some older man who has been around for a while. At some point, this man will lecture you about the Laws of Programming. Ignore this man entirely.
That said, like everyone else I'm going to add my most salient bits:
1. Keep It Simple, Stupid
2. Programming is a lifelong study of the difference between what you said and what you meant to say.
3. Reflect reality in your modelling.
4. If you have to get creative, you might be doing it wrong.
5. Build tests first when you can.
6. You're coding for two audiences: The computer and the future programmer. Favor the latter, because the computer doesn't need help understanding your code.
7. There are two hard problems in programming: naming things, cache invalidation, and off by one errors.