Ebay or Craigslist are probably the 2 most common ways to unload them. However, if you have a large friend list on Facebook, you may want to post it there too.
As long as you have not made an insurance claim or reported the phone lost/stolen at any point, you do not need to contact Verzon. Make sure that you do a master reset on the device and either erase or remove your memory card. Good luck