It's a good park for the big rides. You don't have little kids, which is good because I don't know how the kiddy rides are. My 6yo is big enough for all but several of the biggest rides and makes me go on everything he can go on.
Try to go when they open and hit Volcano first. It's a GREAT coaster, probably my favorite, but it's a very short ride and the line builds quickly, even when the lines are not bad at other rides. There's the new Italian Job coaster, which is tame, with a fast launch that almost made me black out.

I can do the big coasters and almost passed out on that one Go figure. Anyway, the line wasn't too bad, but the lines weren't too bad for most of the rides that day.
As long as you are there at opening and hit Volcano first and then work your way around the park you should be ok.
The food is very mediocre and expensive. The last time we packed a picnic lunch and went back to the car and ate it at the picnic tables. That was a lot better, but since you're traveling you might not want to do that. Also, we ate a "good" (relatively speaking) breakfast at Burger King across the street before going into the park so we weren't hungry early.
There is a water area that I did with my 6yo, but it isn't too wonderful. My 12 and 15yo's didn't do it. Unless it's real hot you might want to skip it.
You can get discount tickets by buying online at least a few days in advance. Not sure how else to get discount tickets besides through local rec departments and
AAA.
You can look at nearby hotels via the Kings Dominion website. I think you can click under plan a trip. I haven't stayed at any hotels so don't know about them.
The atmosphere was ok the 2 times we were there. You will see groups of camp kids. It didn't seem nearly as bad as the local (Maryland) Six Flags, but it's been awhile since I've been there.
I think it's a fun park. We got season passes for this year even though it's a 2 hour drive. We've never gotten passes before and it's not a normal thing, but thought it would be a fun thing for this summer. It's cleaner than what I thought it would be.