The SparkFun DEV-10618 is a very easy way to start using MOSFETS for your next high current project.
This shield allows you to use a computer power supply (or any other power source) to use your Arduino to switch high current. With RFP30N06LE MOSFETS, you can easily control a lot of current directly from your Arduino.
The board provides 6 PWM outputs via screw terminals. Check the datasheet for the MOSFET below for full specifications on how much current this board can handle. A protection diode has been added to the power input of this version of the board.
Schematic design DEV-10618