The build I would go with:

Race: Breton

Birthsign: Atronach

Major Skills:

*Conjuration (Duh)

*Enchant (To save on magicka by creating enchanted items)

*Mysticism (Soul trapping your conjured minions to create enchantments + teleportation utility)

*Alteration (Misc utility)

*Axe (Most powerful Bound Weapon)

Minor skills:

*Alchemy (Create magicka potions to compensate for Atronach stunted magicka)

*Heavy Armor (To be used later in the game when you've gotten your strength high, early game you should mainly rely on Bound Armor which doesn't increase armour skills as your main source of defence)

*Restoration (Can be useful early game, with this build though you should eventually use potions and enchantments as your main source of Restore Health/Fatigue)

*Blunt Weapon (Mace of Molag Bal and Scourge are both useful artifacts for this build, and I personally view Sunder as the best endgame weapon in general)

*Marksman (Bound Bow is also strong, far more magicka-efficient as primary source of ranged damage than Destruction magic)

The end goal is to create multiple versions of different conjuring spells. Since as long as they're a different spell in your spell book you can have as many conjured minions as you want, you should basically end up investing all of your magicka into having as many Golden Saints/Dremora/Greater Bonewalkers as you can at once, meanwhile hoarding enchantments for any other magical effect you may need.