Branson's Biography is worth the read,
awesome mindset. each company is its own business, just shares an initial source of investment and branding. that way if one thing fails it doesn't domino.
and the idea of being the peoples champion, find out what people want and meet that expectation. especially if its an industry that has high customer dissatisfaction (phones, banks etc..)
the story behind virgin Australia is great,
One of his executives who he had success with left and returned to family in Australia, drawing a basic business plan on a napkin over dinner.
(really wanted to foster the culture of people bringing him ideas. and ensured that anyone who left was on good terms to contact him as a partner if they saw a future opportunity)
He had enough trust to let let him run it, all. from memory it was a small initial investment of 1 million dollars? literally the smallest amount possible, as they leased everything in the beginning.
Branson calls it his best investment decision.