1) Read the link REDDOG gave you.

2) Go to Walmart (or Radio Shack or somewhere) and get two FRS radios.
(Similar to these: Motorola Talkabout MH230R Two Way Radios ) DO NOT buy from eBay or other online sellers as you may end up with illegal and unusable radios with non-USA channels.

3) Try to show up on Thursday (Some of us get there on Thursday - Friday before about 2pm, the traffic is very light and we always have a good time - there will be a formal tour on Friday morning and probably 1 or 2 other route options as well.)