Using a dial to adjust values on a LCD display

Hello, I want to be able to use a free spinning knob dial to adjust a number seen on a display and then store that number for later.

Kind of how like car volume dials work. I want to be able to adjust a number on a display from 0.00 to 25.00 in increments of 0.1 and then push a button to store that value.

What kind of components would I need and how would I go about doing this?

Thank you for any possible help.

you're going to need a rotary encoder that outputs gray code

a free spinning knob dial to adjust a number seen on a display and then store that number for later.

I suggest you use a rotary encoder with integrated push button. You store the selected number by pushing the button.
I did something similar (setting up the time) in this project:

Go to Digikey and search for encoders - The select CTS Electrocomponents and detents and Switch. Several options under $5.00. I have used some of these and they make a great panel switch and are very durable.

Sparkfun do Rotary Encoder - COM-09117 - SparkFun Electronics. Its a bit cheap feeling (as it's cheap) but will do the job.

I just got my first arduino(leonardo) and I have it set to send key presses to the computer
A0= prints'a'
A1= prints's' sorta thing.

it works fine

but I am trying to use it as a game controller

I want mario to walk left whenever i complete the circuit, but the computer is not letting the key presses flow through to the game emulator.

the computer is receiving the key presses when i don't have the game emulator running, but it won't control the game.

please help