Well i have been doing some experiments oh what should Olaf build first, and of course this is around the Tank Olaf paired with Atma's. Some say Frozen Malletand others say Warmog's Armorbut have you ever though on Building a Zeke's Herald?

Zeke's Herald has alot to offer Olaf for a really cheap price, lets comepare:

- Frozen Mallet cost 3250 and gives Health, AD and a slow on each AA that means sure dead for almost any enemy who cross you but it cost its more expensive than Warmog's Armor but its easier to build into.

- Warmog's Armor cost 3000 and gives ALOT of Health and Health and can be really efective with Atma's but you need alot of farm to get it .

- now for Zeke's Herald, it gives 250 Health for Vicious Strikes and an Aura of 20% AS and 12% Life steal for sustain and Support + a passive 15% Cooldown Reduction for more PEW PEW with your E more Vicious Strikes and more Ults and AXES all for Just 2145 Gold! and its also stard with the Ruby Crystal that you would normally get (at least thats what i have seen so far and what i do). Its a really Cheap item with alot of things to offer olaf and still have sinergy with Atma's Impaler, if you add Frozen Mallet you will get even more health to exchange to AD.

This is what i thing about what item Olaf should start with because its helps you alot in lannin phase or even in the jungle, as i know Jungle Olaf Use Vampiric Scepter, and had worked for me.