Warm colors and texture. You need a comfy pouf or ottoman with a throw and some soft drapes in a warm color. A tall green plant behind the lamp would also look nice and a side table for that cup of coffee or glass of wine.

This picture is very dark which makes it difficult to see what the room really looks like. I would like to see the shelves, but off hand I can say add some color with drapery panels and throw pillows and an throw. A nice painting or print above the bookcase would be a welcome relief as well.

Paint the walls a soft chambray blue. It's hard to tell what colour your arm chair is, but if its brown, grey, blue, or green it would look lovely. Add a small round or hexigon side table so you can put a cup of your favourite beverage on it and your book if you need to get up, and a small lamp. You could soften the windows up by adding drapes white & blue are classical in any setting. Then add your favourite coloured vases, bookends, mirrored picture framed photo's and nic nac's to you bookcases and viola!

I would add something hanging from the ceiling, maybe a chandelier, or some paper lanterns (there's not even needed light in...)
and something on the bookcase, maybe some vases or other statues (not too much).
and of course some curtains.

I WOULD EXIT THE WHITE METAL BLINDS AND PURCHASE WHITE OR BROWN IMMITATION FOE BLINDS. EXIT LIGHT, VERY 70"S. GET A MATCHING FLOOR LIGHT FOR READING CHAIR AND DESK LIGHT. ALSO EXIT DESK GET A DESK TO MATCH WALL UNIT OR CONTRASTING COLOR. WINDOW GOES DOWN TO FLOOR GOOD FOR LIGHTING BUT NO PRIVACY. DESK MODERN, LAMP IS MODERN WALL UNIT CONTEMPORY CHAIR TRADITIONAL RUG JUST THERE SERVES NO PURPOSE. I LOVE WHITE.I WOULD 1ST FIND A RUG WITH LOTS OF COLOR( LARGE PRINT, ABSTRACT OR LARGE FLORAL.. THEN PICK A COLOR OUT OF THE RUG AND DO THE WALL WITH DESK & WINDOW 1ST. IF YOU LIKE IT DO THE OTHER WALL WITH WINDOW. IF YOU REALLY LIKE IT DO THE 3RD WALL. GREAT IDEA ADDING ABOVE THE WALL UNIT. IF YOU PAINT THAT WALL A POP COLOR GET MANY PICTURE FRAMES WHITE AND PLACE COLORFUL PICTURES ABSTRACTS, TO MATCH RUG. THIS ALIMINATES DUST CLUTTER AND YOU ARE USING ALL YOUR VERTICAL SPACE. IF YOU DO NOT PAINT 3RD WALL USE THE COLOR PAINT ON WALL TO PAINT PICTURE FRAMES ODD # 5 LARGE. 1 CENTER WALL UNIT 1 ON EACH END THEN CENTER OF BOTH. HAVE FUN. THIS WILL INSPIRE YOU.

Your bookshelf and modern desk and lamp seem to indicate you like a contemporary look. Studying your image, it looks as if the room is bottom heavy. You have a large expanse of space above it to the ceiling. A radical suggestion is to purchase a number of black square picture frames just slightly larger than the "boxes" in your bookshelf and fill them with pictures and hang them high around the room (5 on the long side and 3 above the window). What these do is create a "band" that will occupy that space. Don't put busy pictures ... images that focus on a nature (leaf detail, snail etc) or architecture mean people don't have to peer at them to understand what they are about, but they add additional interest in your room.

It would be great to frame out your windows or at least the back window with a structured contemporary valance that comes all the way across. Give in some height, don't be afraid to get close to the ceiling. A black, white and grey tone print fabric would give you some interest and still keep our monochromatic look. I would throw a couple of long linear sculptural pieces across the top of the bookshelf and break the room up with a great rug, something lighter that has touches of a bold color, or a graphic tone on tone,whatever it is, you have to love it.

I wouldn't be able to read in here either. It's dark, stark and cold. It needs to feel warm and cozy or light and airy, but regardless you need to LOVE IT.

I think paint and window treatments would be the most helpful. Pick your most favorite color that relaxes you, and since it's a small space, go for one of the lightest shades to paint the walls.

Also since it's a small space you don't want window treatments that are going to be overbearing and cumbersome. But I don't have any real suggestions cause it will depend on you personal taste. Somehow the shadows cast from light peering through the blinds is adding to the dungeon look, so make sure anything you get to replace them does a better job of keeping out the sunlight when that's what you want.

I loved ASVinteriors idea of the square picture frames to draw your eyes up.

Here's my radical idea. From the picture you cabinet looks like a colony of mini caves. Since the piece is so dominate I think you should brighten it up and personalize it. You could have a lot of fun with this. I have two ideas: one to make it a piece of art and one to make blend with the wall it's against. For the idea to make it a piece of art, paint each cubby different using two accent colors and creating a pattern of some sort, maybe a checkerboard pattern. The other idea to make it blend with wall would require two more shades of the same color as the wall it's against. Paint the face of the cabinet, the skinny lines dividing the cubbies, the same color as the wall behind. Paint the outside and inside walls the next light shade. Paint the back walls of each cubby two shades lighter then the wall. They won't look like little caves if the are somehow getting lighter towards the back. Maybe also paint the ceiling in this same lighter color.

The floor and the couch are too dark. A bright colorful rug and a light slip cover will help.

Thank you for all your ideas, definitely will consider all your input :)

I would add some drapery it will really finish the look and give you a pop of color. I recommend mounting a rod 6'' above the frame and the panels should be 24'' wide each.

@ Loretta Callejas...when you use all caps it indicates you are screaming - just so you know. :-)

I would definately add drapery panels to both windows. Remember to hang as close up to ceiling as possible. Fill the bookshelves with all your favorite books. And, maybe add some greenery. Like the small plant that sits on the table in the photo above. Little touches.