I am trying to control the speed of a DC motor with a micro controller. Can someone reply with some resources?
You didn't tell us what microcontroller You are using.
Or what programming language.
Or which motor and its specs: Voltage, Current draw.
And if the motor draws more than a few 10's of mA then you need a driver circuit.
Do you the motor to run in both directions (CW & CCW)? or just one direction?
This will determine if a simple transistor switch or a full H-bride is required.