I'm getting Piplup too, but I'm not letting it evolve. I'm just breeding another one and make the new one evolve just to get its data in my Dex. Anywho...
Piplup learns...
Pound
Growl
Bubble
Water Sport
Peck
Bide
Bubblebeam
Fury Attack
Brine
Whirlpool
Mist
Drill Peck
Hydro Pump
2nd Evo learns...
Tackle
Growl
Bubble
Water Sport
Peck
Metal Claw
Bide
Bubble Beam
Fury Attack
Brine
Whirlpool
Mist
Drill Peck
Hydro Pump
3rd Evo learns... (New Attribute! Steel!)
Tackle
Growl
Bubble
Swords Dance
Peck
Metal Claw
Swagger
Bubble Beam
Fury Attack
Brine
Aqua Jet
Whirlpool
Mist
Drill Peck
Hydro Pump
http://serebii.net/pokedex-dp/393.shtml