Speaking as somebody who's family was brought together by MGS, it is an absolutely immutable law that you play MGS1 before any of the sequels (playing Metal Gear any any of it's pre-MGS sequels would also be a plus) - Ideally on your own at night, so at certain points you can feel free to let that single solitary tear just roll down your face.

Also, on a practical note - as the game progresses avoiding guards becomes far easier than taking them on, so it never hurts to practice. You could also get the extra disk of special VR missions. firefly99, do you remember that one where you had the guards walking around the goal in a circle, occasionally stopping to change direction? Completing that was one of the high points of my life.