If you're looking at this guide, either you're a Nasus main, or you remembered that it exists and felt the urge to farm with Q.
Regardless of what the reason was, this build will upgrade Nasus gameplay, giving him the ability to fight earlier and, therefore, farm more easily.

Early game:
It's very simple, you will farm normally, and if you feel that the enemy is abusing you too much, slow him down and beat him up until you feel like you can start farming again.

Mid game:
Same thing, but now you can walk around and farm people because now you have damage for that, but REMEMBER to only do this after buying at least Hexplate and/or Trinity Force.

Late game:
Now you have the ability to 1v5 easily, but don't be stupid, make sure your Ultimate and Hexplate are available.


Overall, this build is strong, but it's not meant to be used all the time, with great power comes great responsibilities.
I recommend using it when the enemy team has at least 3 melee champions.