Hi Micheal,
I'm assuming you are talking about welded structural steel moment connections in a building? There are bolted moment connections also, but you are asking about bevels and weld sizes. The AISC has publications describing these connections in detail from engineering all the way through to field inspection of these type joints.

FEMA-350 also has design criteria for new construction steel moment framed buildings in seismic zones. I guess we need a little more info on the moment design that you have in mind, as there are several design concepts dealing with moment connections.
John Wright