Always consult Sheldon Brown, ParkTools.com, or a bike mechanic before trying complicated bike maintenance for the first time, especially if its your only bike.
Boy! I could have used that one a time or two. But if I may let me add the Bike Forums to the list.
My tip:
Check your cleat screws before riding. Make sure they are snug. Nothing like trying to clip out in a hurry and not being able to.
Can you say:
I've fallen and I can't get up?