Hi im a level 27 player on the Na server. I like to play Nasus as a tank but he can still do damage with his q which is op imo.

I am not good with runes. Mebbe cooldown reduction and mana for aggressive laning and armor and magic resist for more passive lane. Scaling mr if the enemy laner is ad, scaling armor if the enemy is ap.

I like to go 4-21-5 because Nasus is a mana hungry tank. He needs to spam q a lot so get cooldown reduction.

Well for start i like doran's shield cuz its cool... and tanky. You can get a mana potion instead of health. Start randuins omen if the enemy ad is fed, spirit visage if ap. then by armor, magic resist, armor, boots, and situational.
I see nasus players building Nashors tooth but usually they lose...
Banshees Veil is a good item.
Black cleaver if you are fed.
Dont go over 40% cdr
Locket if the support didnt get it.
Iceborn gauntlet or trinity if fed.
Warmogs is also an option but get it after mr and armor.
Sunfire can combo with your ult but it is annoying when walking through the jungle.
When you are done with your build remember to get elixers.

Obviously max q for damage and lower cooldowns. You can max e or w whether you want damage or utility. Usually one point in w is good enough. Maxing it is overkill.

Ghost cuz nasus is really slow. Teleport so you wont fall behind. Ignite if you dont want tele. Exhaust is pointless unless you want to combo with w and make enemy feel like they are walking backward.

I havent played ranked yet buy i think nasus will not be good in higher elos since people will know to deny you your qs.

Pros: Monster late game
does surprising amounts of damage
cons: only good skin costs a lot
bad early
vulnerable to silences
its basically a 4v5 during mid game since you are farming
sorta boring early

Nasus can jungle but i wouldnt advise it.
Max e instead of q but put a point early.

Nasus doesnt have team work at all early to mid. He can tank everything and get killstealed late though.

Farm Farm Farm. Nasus is like a farmer. Do not leave lane unless a lane is pushed to inhib turret. Conserve mana early game by only using q. I used to use e all the time and that wastes mana. You will have to back early. Dont push your lane so you can safely farm creeps. Dont be afraid to take a few hits from the enemy laner to get your stacks. You should have at least 400 stacks by late game.

Dogs are good at tricks so... yeah. These are actually mostly tips. Your ultimate does a lot of damage so you can pop it in teamfights. It gives bonus health so use it in sticky situations. You get bonus range so you can use it to fetch the enemy champ. E reduces the enemy armor. Wither also slows attack speed so use it on tryndamere. Use your q to reset your auto attack timer. If you are against someone like Hecarim who has a lot of movement speed or someone like Tryndamere who has high attack speed, you can max wither second.