Calibrating Studio Display with the Datacolor Spyder Pro

Really basic question here from a newbie to calibrating: I have a Studio Display connected to my MacBook Air and have just purchased a Datacolor Spyder Pro. All firmware is fully UTD. Does the calibrating device actually adjust the monitor settings according to the calibration results, or do I need to calibrate manually? If the latter, can someone suggest a link to learn how? I'm an amateur photographer and want to make sure that what I see on the Display is what I'll get when I print, upload, etc. I have looked at several articles at Apple and videos on YouTube, and they seem to assume that the reader knows the basic mechanics, and I don't! Thank you!