There are hotels in the area, most are about a half hour drive or so from the venue, we stayed in Yakima,WA the first year I went. Camping is definitely the way to go though, most people either stay at The Gorge campground or Wildhorse (http://www.wildhorsecampground.com
). You would most likely fly into Seattle/Tacoma but Spokane is also an option as well, whichever works better for you. Either way you will need a car because it's a about a 2-2.5 hour drive from either airport. All other supplies would really depends on whether you camp or stay in a hotel.
If you really wanted to get the whole experience I'd recommend staying with Toupstown at Wildhorse. Check out http://toupstown.com/gorge.html
for all the info. Keep an eye out on the site for it to update for next years shows.