I have put together many of the Sapien bookcases by Bruno Rainaldi- both the Design Within Reach and the CB2 versions. (Both version are designer by Rainaldi and both made in Italy) And having done so, I have a few tips on putting them together that I thought I would share... especially if you are doing it yourself!
By yourself seems like the biggest challenge with the weight of the shelving. The tips below should make your this DIY much easier. Then, all you are left to do is stack it full of books.
For the large bookcase from Design Within Reach you need 4 DVD cases, a blue-ray case and two of the shelves stacked. (Yes, that is that is "The Sisterhood of the Traveling Pants 2" on the bottom. It's a guilty pleasure of a movie! )
For the small bookcase (CB2) you will need the 4 DVD cases and the blue-ray case.
Remember lefty loosy, rightsy tightsy to quickly install the screws. I like to tighten them, then place the shelving upright and checking for stability. Them lay back down and re-tighten.