business travel accompanying spouse & child

First, prepare the relevant documents including passport and its copy, the application form, a passport-style photo, and an invitation letter from your business partner. Next, go to the CVASC to submit the application.
As for your wife and child, they can apply for a tourist L type. Those documents are needed: passport and its photocopy, the application form, a passport-style photo, hotel reservation and round trip air tickets.