As a Chinese, I applied for H-1B to work at USD. Before the application, a petition for Nonimmigrant Worker, form I-129, was filed on my behalf by USD and approved by USCIS. After that, USCIS sent me a Notice of Action, form I-797, where I got a receipt number to fill the DS-160 non-immigrant visa application form online. I then used the DS-160 confirmation number, the start and expiration dates of the petition and the receipt number to schedule a visa interview.
My family needed to apply for H-4 visa. The whole family had to fill the DS-160 non-immigrant visa application form online including kids. They needed exactly the same things as me, the H-1B applicant, to schedule a visa interview.
Since March 2013, one can choose where to apply, pay application fee, and schedule interview online at http://www.ustraveldocs.com. This is where one can fill in the DS-160 and I-797 information. If the H-1B and H-4 applicants plan to apply together, there is no need to create separated account for each person. The H-1B applicants can add dependents in his account, pay application fees for all of them and schedule interview together. Unless an H-4 applicant needs to apply alone, DO NOT create separated account for this applicant, otherwise, the system may complain about duplicated profiles. If the H-1B applicant pays the application fees for the whole family, only ONE receipt number will be provided. It can be used for every member. Please use DIFFERENT email addresses for each applicants. It seems that the system regards email addresses as accounts. The same address for different accounts may confuse the system.