Well if you know the name of some of the conventions you want to go to that would help. I say that because as it is now several conventions have their own web sites. So you look them up and see when and where and quite a few have mailing lists. Some I can thing of right now are:
Megacongame organizerStar Trek/Buffy ect.GenconAlso you can check out what convention centers are in the area your going to travel to and se if they have links to the conventions that are being held. You can get information from the company that makes the game like going here:
FanPro upcoming enventsIn essance there are lots of ways to find out but they do require some work on your behalf. Also like I said once you find the convention you want you will probably find an email list to sign up for as well. Hope this was of some help have a nice day