Step 1: Negotiate what you want/need/expect from your advisor, and what the advisor will want/need/expect from you.
"Questions to Ask to Help Select an Advisor" will help you consider when to ask for help, what sort of help/response is likely to be most helpful for you, and how to shape roles of committee members.
Step 2: Work with your dissertation committee chair to set up your committee
Take time to come to a clear understanding of why you are selecting each person; how, why & when to interact with the committee throughout the process; and special roles you might need members to take on – for example, maybe one committee member will be "a support editor" who monitors style, formatting and professional standards.
For a discussion of these points see guidelines at Gallaudet University.