First, read through all the instructions before you begin so you can figure out they miss a few important steps. 
1. The middle support bar needs to have all the holes facing up. The diagram doesn't show this.
2. You should probably screw this into the footboard as well...instructions leave this step out.
3. Some of the holes for my side plastic pieces were about 12 inch off. I had to drill my own holes for a few of the pieces.
4. Before you put in the center plastic pieces to hold the slats in, you need to put the slats in both sides, then the center plastic piece, then pound the centers into the middle support bar. The slats don't bed to allow you to slide the slats into the center plastic pieces after pounded in. 
Other than that, this bed is great!