I'll save you the time:
With media:
1. Learn what journalists would be interested in your company (and why).
2. Send them regular updates about what your company is doing (in press release form or, better, as a personal email).
3. Be honest with them. Talk from the heart. Avoid exaggeration and "marketing language".
With customers:
1. Always say you're sorry when you screw up or when they're unhappy (for any reason).
2. Communicate as often as you can via all relevant channels...
3. ... while avoiding spam and "marketing language".
If you ever get big enough that journalists are coming to you, hire a specialist.
