BenQ T720 (calibration)

I have a monitor BenQ T720 3 years old. However now with my entry into the digital photography do not know if this is the ideal display for editing of images as I have already noticed that the prints are different from what I see on the monitor. Already saw in various printers and print them always comes out the same, but different from what is on screen. So I guess the problem is the monitor ... or I just need to gauge a monitor? How? This monitor is good for the image editing, reasonable, poor or mediocre?
I await an answer!

Make a span of the monitor, if you have nVidia video card, the card's control panel has a good gauge. Else you can try to gauge from Adobe. A calibration by software will never be the same as using a professional calibrator, however, is very good if you have patience and preferably with the monitor turned on for at least an hour and using the ambient lighting the way that most uses the monitor.