How to voltage divide down a single ended analog signal?
Putting resistive voltage dividers in front of ADC inputs is a rather common design technique. It's done even in highly sensitive instruments (there it will be a somewhat more complicated RC network, but the principle stays the same) so your uC project will be just fine.

But, of course, such questions were asked before:
How to Convert 0 to 10V analog signal to 0 to 2.5V for ADC input?