How can I contact with professors of well-known universities?

Answer 1

Most university websites have information about faculty, including contact information. You usually find it (at least in North America) by going to the tab on the home page which says "Academics", then there will be one which says something like, "Schools and Colleges or Faculties". Pick the area you are looking for, and within that you can pick the appropriate department. Within the department there is usually a tab for faculty, on which you can find this information.

Answer 2

there is usually a faculty roster on the school's website.