How do I properly light a closed room?

I’ve got a few simple low poly objects inside a room and I’m trying to light it properly but I don’t know where to begin.

I’m trying to emulate the room I’m typing this in. I’ve modelled my desk, and the monitor, and an empty cup on a reflective coaster on the desk.

I started by putting a single lamp on the center of the ceiling much like the real life room, but it looks…godawful. I turned on radiosity but it doesn’t seem to be doing much.

I read a radiosity tutorial thing, and it says that I shouldn’t use lamps? That only objects with an emit factor > 0 should be used. Is that right? Will radiosity not work with lamps?

This is the most recent render. I ask you ignore that stupid sphere floating around. That will later be modelled into a mouse. It was not intended to be in the camera view.

Also I’d like to know the easiest way to soften those shadows signifcantly and get soft llight instead of hard?

I’d appreciate your advice. Thanks.