Over on Quora, actor Ashton Kutcher recently left a detailed answer for a user who asked the question "How did Ashton Kutcher prepare for his role as Steve Jobs in the new movie 'Jobs'?" His answer on the site (in which Kutcher is an investor) was actually quite revealing, not only about how an actor prepares for a role but also pointing out some personality quirks of Steve Jobs.
Kutcher started his preparation by reading the script, watching documentaries and interviews, collecting YouTube content, and listening to Soundcloud files of Job