Berserker help

What be a good weapon expertise to choose for a dwarf berserker?

Selectable skills, which can only viewed by classes that get them, are not really something to chat about here.

Best to chat about it in game with others of your class or warriors who get similar lores and expertise.

In my opinion of all selectable skills, do what YOU want. If however you are unsure, or can't make heads nor tails of the subtlety in the helpfiles, then see Chayesh's post above about asking in game.