Go to http://b2b.vzw.com/international/Roaming/index.html for more information about international use for your device. Also, you can call *611 from your device and find out more.
You might also consider would it be cheaper to buy a pre-paid phone in Mexico for calling. I have never traveled out of country with a cell phone, so you might check all the angles to see which will cost you the least.
I have provided a link below that will take you directly to Verizon Wireless Plus Mexico calling plans. This will provide you with everything your need to know about your options for using your phone in Mexico: