- Dash-to-Dock (highly recommended)
And here's - How to enable Desktop Icons.
The main productivity thing I love about Gnome-Shell (and it's kin: Cinnamon & Gala), is dynamic activity management. I'm a visually minded person, so keeping things spatially separate really helps me categorize my work. It makes me more productive, and less frustrated. Sometimes I'll have 5-8 difference activities open, so having dynamic activities which scale to my needs on-demand is key.
That's not to say Gnome-Shell doesn't have it's flaws and short-comings. It does. However, I don't think "productivity" is one of them. I get very frustrated with Windows these days cause I can't separate tasks well (or middle-click-push windows), and fixed-count-activity DE's like Unity/Xfce/etc feel much more restricted.