Raging nerds will tell you that the walls must be perfect neutral grey, but that's so inhumane in my opinion. As long as they're fairly neutral, it'll be fine - white or cream or very pale brown or whatever.
If a window is unavoidable, try to have good blockout curtains, and generally, I'd advise having it at the side of your seated position. In front of you (behind the screen) will throw glare into your eyes, and behind you will throw glare onto your screen.
The position of the light globe/s is an interesting one. I have a long fluro bulb, and after trying various positions, I found I liked it best when it was directly above my head. Kinda the same principle as above - if it was in front of me it got in my eyes, if it was behind me it glared on the screen.
Desk? Well, I love my standing desk. But it's not for everyone, I'm sure.