Well, ReadyBoost is a feature where you connect a flash drive/SD card/etc into your computer and Vista will use the space on the flash drive to make the computer boot more quickly.
All you have to do is connect the drive and when AutoPlay comes up, just select the Speed Up My System option.
You will be taken to the ReadyBoost tab of the flash drive's properties and all you do is make sure it has the radio button set to Use This Device. Couldn't be much easier.
