I love this place! I've been wanting to see this every time I go to Vegas and I was finally able to make it!
The rocks are very easy to find with the address listed on here. Be careful for parking. Make sure you park in the further lot. Although it seems farther, it actually works out better because it's closer to the entrance of the exhibit.
When you're walking towards the rocks, you'll see signs on the floor (probably not the best place for those) where you call in and they will tell you more details about the artist and the exhibit.
The best place to take a picture with it is if you walk really far away from it then you can actually see all 7 rocks. Also, then it's a little more quiet when you're far away.
There's a lot of dirt everywhere because I mean you are in the desert, so wear tennis shoes or shoes you don't mind spending a lot of time cleaning.