I've got an Assassin and Warrior build, so I decided to make a Mage so I'd have 3 different save files with 3 different playstyles.

I've never really gone the full magic route in Skyrim so I'd be grateful if you gave me a few tips and suggestions!

So far here's what I've decided:

Race: Breton

Primary Skills: Destruction, Conjuration, Restoration and Alteration

Secondary Skills: Enchanting, Smithing (?) and possibly Speech (depending on how many points I have left)

Choice of clothing: Robes

Moving on to the schools of magic, in destruction I don't know whether to choose just one of the elemental
spells or all three. Which is the best? Fire, Frost or Shock?

I only want to delve into Atromancy in the Conjuration tree so I pretty much know what to do there.

As for the others (Restoration and Alteration) which are the best perks to take and what spells are the best?

Some of you guys are obviously more experienced with magic in Skyrim than I am, so I'm more than happy for you to give your opinions and help point me in the right direction! I just can't wait to finish work and get started!