started with some cubes

delete a face to get a window.. also i thought that making a round window would look cool.. so i used booleans to get it round

used booleans to get the round window.. later decided to change it to a more traditional style window

this is my window

made the structure grinds from simple cubes

i duplicated some sphere with the setting shown to get the nut bolts

here s my room so far.. please notice that i wanted the walls not to be perpendicular, and to have an angle

here's how i started to make the couch

the finished couch

started to make the glass table in Corel X3.. u could use Ilustrator also. The CV curve tool in Maya doesn't has that much control over the shape, so decided to make it in Corel with the pen tool

i used booleans to make my table feet

some random decoration to put on the shelves..

here's my shelv made from cubes and with booleans

here's my final setup.. Used an area light at the window with no light emiting, only photons. Unfortunately i used to few global ilumination photons and as a result u can see some shadows on the wall ( mostly because they are not perpendicular ). I used 2000000 caustic photons and 30000 global ilum. Although ur scene my be different in size. Also, i used a plane with a surface shader and final gather cranked up to force some interior light
Used a directional light to simulate the outside light source and a plane with a ramp plugged in. After the render ( 3 hours ) i added the cloudes manualy in photoshop... it was easier than rerender.
PS: the courtains were done using 2 curves and birail tool