Attack effects before doing damage?

[MCNewfall]

My opponents Cleffa is asleep. I use Magnemites "Thundershock" and flip heads. Paralysis overrides sleep, but does that happen before or after the damage?

Likewise, I use Typhlosion's Flare Destroy to knock out my opponent's Yanma with a Rescue energy attached. Do I discard the rescue first, thus sending Yanma to the discard?

 

[PokePop]

Damage always comes first. Cleffa is still Asleep and damage blocked. Then it is paralyzed.

A Pokemon is not discarded for a Knock Out until you have finished everything that you need to do for an attack, including effects. The effect would discard the Rescue Energy and then, after that is done, Yanma will be Knocked Out and sent to the discard pile.