Where Does The Credit Go?

So...because I am particularly new to this still; meaning the book blogging and giving my personal reviews and taking part in fun activities such as The Sunday Salon, Booking Through Thursday, Tuesday Teaser, etc... I wanted to make sure that people who don't know where these ideas came from and what have you, that the credit goes to the right person. So I had started saying in either the beginning or the end "Powered by so and so" but I am fearing that I may not always be right. So if I am wrong and you come by and see my mistake please leave a comment for me on the blog so I can fix it! Hopefully I have been giving the credit to the right people so far:)