Immediately, the children went nuts
I actually finished the shelves a week or two ago, but had them lying on the floor because I wasn't sure how I was going to hang them. Finally, I bought and tinkered with some dry wall anchors only to find out that there was a stud in the exact spot in which I wanted to hang them. So, I ended up just screwing them straight into the wall (after pre-drilling, of course).
Here's what the twins were doing while I was hanging the shelves...
Must run. Gotta get to work on the cubby storage system!