I've made my own video for this in the past, and to make it extra effective, I made it a video adaptation of a text guide. You will have two sources to verify you got the symbol, so you can make sure you haven't missed one.
Text Guide (by Thortok2000):
http://forums.steampowered.com/forums/showthread.php?t=12901...My video adaptation of this specific guide:
Good luck!