Once your Monk reaches level 70 (perhaps with a help of a leveling build), you will be in a prime position to pick and work towards your Build. Keep in mind that your Build will not only define your gameplay going forward, but also your optimal armor and weapons.
Below you can find some of the best Monk builds for Diablo III.
LoD Wave of Light
(LoD refers to the Legacy of Dreams Legendary Gem)
A powerful build capable of dealing massive AoE damage. It does not rely on any sets, but rather a few legendaries to enhance your Skills. Damage on this build will primarily revolve around Wave of Light.
Inna Mystic Ally
An intuitive and extremely powerful build that can be used very effectively for many situations, especially speedruns. Damage on this build will primarily rely on Mystic Ally.
PoJ Tempest Rush
An easy to use and versatile Build, it allows you to run around and drop ice bombs on enemies. Damage on this build will primarily revolve around Tempest Rush.