Hi Lloydy,
A vid of the snatch balance.
http://au.youtube.com/watch?v=Inc7kjUf2KQ&feature=related
Obviously start with a dowel rod first and make sure you can behind-the-neck press and OH squat.
The following vid is prob better for you to learn some of the movement patterns and progressions. Sometimes we’ll do 5 rounds of 5 reps each with a dowel rod as part of our warm up:
http://au.youtube.com/watch?v=pDuZAXYvwO8
Crossfit.com has some ok demo vids on there too for the o-lifts.
Cheers, hope this is helpful.
Dan