Controlling DC Motors with direct PWM signals?

I have an arduino uno, and I'm wanting to control DC motors with PWM signals. I'm aware that I'll need an external power source for the motors.

I'm extremely new to this kind of hardware. Is there a general tutorial that I could take a look at to help me along?

Thanks.

Try this:-

Also which motors are you thinking of? You need to match the motor driver and
supply to the motor, and realise you power it separately from the Arduino.