Monk weapon question

[nineonesix]

Hello blue,

I was curious about the when and what of monk weapons..

as in..
I duel wield until 20 if i recall?
And after 20, i would switch to a 2h? I would be normally soloing, but will be ready to group if needed. If anyone can refresh me on how monk weapons and bonuses work, i would greatly appreciate it. Thanks!!