If you’d looking to quickly style your map without resorting to CartoDB or D3, you could definitely do worse than QGIS.
Add your layer(s) using
Layer > Add Layer > Add Vector Layer (or however you’d like to do it). I’m styling a shapefile of New York City school districts based on after-school program enrollment.
Right-click your field, then select “Open Attribute Table” to see what columns you have to work with.
ENROLLMENT would be a good one to work with.
Right-click your layer again and select Properties.
Now from the left-hand tab selector, pick Style.
In the upper left-hand corner where it currently says
Single Symbol, change the dropdown to read
Graduated. This means we’re going to change the color gradually based on a column.
ENROLLMENTfor the column to base the color on.
To learn more about modes, check out Graduated Color Modes.
Looking good! Feel free to hop back into the Styles tab to change the mode, or even manually set the color bands.