Quick answer:
Small, clean spills caught early, mopping, drying, running a dehumidifier, are fair game.
Call a licensed water-restoration company when water is contaminated, has spread into walls or subfloor, has sat more than 48 hours, or when you smell mustiness (a mold sign).

Make it safe
Handle immediate hazards first (electrical, structural, contamination).

Find the cause
Fix the source, not just the symptom, so the damage doesn't return.

Repair from the inside out
Structure and systems before surfaces.

Maintain
Protect the work you paid for.
How long do I have before mold starts?
Can I dry out water damage myself?
Should I call my insurance?
Is standing water dangerous?