In decorating anything, every single detail counts. Whether you choose curtains, blinds, or neither of the two counts. The color scheme counts. The material of the furniture counts. Most importantly, the furnitures and electronics located inside your office counts.
Even the choice of the silent bookcase counts.
Of course, the bookcase counts. Fewer are serious with their bookcases nowadays because of the Internet rage, but it still adds some air of intellect and seriousness inside an office. I personally prefer wooden bookcases than the metal ones since they look classier. I like classy things. I am not imposing on you that that is better, though. It still depends on the mood you want your office to have. If you prefer to have a very busy, modern working atmosphere inside your place, then go for metallic designs. You can never go wrong with them as well.
And it doesn't end in choosing the right furniture. There's also the task of choosing where they can be put best. I am not an expert about this kind of stuff as I am not an interior designer, but there are things that you should not forget, interior designer or not.
Play with the light. Use it to your advantage. You shouldn't put up large furnitures in front of the window. You're wasting light. I'm telling you, light is a precious source that you should not waste.
Also, know where things go. Corner bookcases goes to the corners, obviously. Tables, on the other hand, usually go the middle of the room--unless it's a side table, of course.
Interior design isn't that difficult. Just a little bit of research and creativity and there you have a great home office.