If I want to make a character focused on Restoration, what skills should I focus on as secondaries? Maybe enchanting so I can decrease magicka costs through enchanting? Maybe Destruction for damage? Suggestions?
Restoration as a "Primary" is difficult, since that's not really a way to "solve your problems", as it were, unless you rely upon companions to do your killing for you. I would suggest Conjuration and either having a heavy warrior type of companion with the dog, or else a character who stays at long range, and lets those summons do the dirty work. You can then just go pure HealBat and pump out heal other spells constantly on whoever is doing your fighting for you. Illusion can help, as it lets you control the enemies, or just go invisible if you are getting too heavily pounded on to cope.
Alteration would also make some sense if we had the ability to target others with protection spells. Likewise, Restoration lost many of its best spells in the likes of fortify attributes or skills that you could toss onto allies.
Otherwise, if you don't just want to hide behind others, go "DnD Cleric", and take armor, shield, and mace into battle.