Need some simple help with this circuit

[weksos]

I am working on a project in which I have to attach a hydrocarbon sensor to a microcontroller in order to read in the voltage and know if the sensor has detected something. I have attached the circuit for the hydrocarbon sensor. As you can see there are two resistors in parallel so the voltage will be constant. We need to figure out what supporting circuitry will be needed in order to read a voltage and amplify it so that our microcontroller can read it. We were thinking of connecting an opamp or two to amplify our signal, but we are not sure how to connect them to the sensor.

We are really confused and need a good, easy-to-understand explanation. Any help would be appreciated.

Thanks!

http://s.eeweb.com/members/laura_webb/discussions/2013/02/19/COBRA-MODEL-100-HC-schematic-1361297798.pdf