There is a guy in the Pokemon Fan club or the Misralton Pokemon Center. Forget which area exactly that tells you your hidden Power type. However I don't know what the IV's you need to get that. Just keep breeding and checking with the dude until you get it XD.
For Sceptile you'll want the following EVs:
HP:31 Atk:30 Def:30 SAtk:31 SDef:31 Speed:31. That is the best combination to get a maximum power Hidden Power Ice for Sceptile.