At a quick glance, here's everything you need:
4 Wooden Crates (get them at Michael's or Jo-Ann Fabrics)
Wooden legs (optional - Home Depot)
Wood stain or paint (I used paint)
And well basically just put them together (see step wise instructions above) and you have it!
Now too fill it up with books and other things just flying around the living room.
Happy creating! :)
After adding stuff (The colors are different I guess because of lighting issues) :