Data from a webpage into a program

I am really not sure where to start.

I have a Yun based sensor station that collects data and uploads it to a database.

Right now the users of the units have to edit the arduino code to change the calibrations for the sensors that are plugged in (Users can change the sensors that are connected.). For some of the users, this will be no problem. For others this could be hard and introduce errors into the system.

I would like to know if there is a way to have the user access a page on the device and put the values into the page to be sent somehow into the arduino program.

Anyone know how I could do this?

I am mostly looking for a pointer to some tutorials to help guide me and I am pretty sure someone else has tried this.

You can check out the Bridge tutorials

The "/arduino" directory doesn't have anything pre-configured. Anything added to the URL after the end point is passed from the webserver to the sketch on the 32U4. You can define your APIs inside the sketch. See the Bridge example to see how this is done to access the pins on the board.

So you can create your own API based on that, send '/arduino/calibrate/sensor/value, and then on the arduino parse the string and change stuff based on the recived input.