“Oh that, the monitor I bought 5 years ago came color calibrated.”
Calibration should happen annually, at the very least, and monthly or bi-monthly if you handle critical color. This will help ensure the most accurate color match from screen to proof to press. Understand that individual printing companies have different press standards and types of ink, so your calibration settings may vary from company to company. Pick a company that produces color printing to your satisfaction.
The highest level color standard in the printing industry is Gracol G7 certification. It is an international standard and printers must go through a rigorous color-match testing process to be certified. Color standards must be met annually in all steps of the process: prepress, proofing, and press. All equipment must pass the testing for a company to be certified. The goal is to ensure that print in Portland, New York, and Bangkok could meet a consistent printed color standard.
Accurate proofing is necessary for critical color. Color adjustments, enhancements and tweaks can easily be made at the color proofing stage, but not on press.