@Imweightless2012
Well, if I'm going to use a picture of an actress as a book cover, I usually just edit it using a picture manipulation program.
If I think the picture looks nice enough as it is, all I have to do is just add the book title, maybe add some special effect here and there using picmonkey.com (which is easy enough for anyone to do); but some of the book cover sometimes require more complex editing, sometimes I have to join two pr more pictures into one and make them look good together - that's where some photoshop skill is required.
I think most of the people who make book cover often edit their pictures, at least, to make it looks slightly different from the original to avoid copyright problems. Maybe that's why you can't find those precise picture in google easily. Hope this help.