Any scientific endeavour should be based on a scientific attitude and state of mind based on rigour, scientific method and integrity, but also a (self-) critical altitude, curiosity, and fun. No other person I am aware of represents this so well as R. Feynman, physics nobel price winner (1965). He died in 1988, but his writings and recorded interviews continue to be highly regarded and referred to in and outside the scientific world. Besides his contribution to physics he remains well known for his contribution as a member of the Roger Commission investigating the accident of the space shuttle Challenger (more precisely his minority report).[More here]

I recommend to read Feynman. There is no bette introduction to the scientific mindset, no matter the discipline, instead or before any text on scientific methods in your field.

Besides his still famous and highly regarded Lectures on Physics (early sixties), he has published many books meant for anyone interested in scientific activities. He is one of the very rare authors able to convey a scientific attitude and mind-set that is pleasurable to read for everyone. Titles like The Pleasure of Finding things out or You are surely Joking Mr. Feynman reflect this.

• Feynman, Richard P., Surely you’re Joking Mr. Feynman! Adventures of a Curious Character, New York, Bantam Books, 1985. French translation: Vous voulez rire, Monsieur Feynman, Editions Odile Jacob A lire pour comprendre comment un des physiciens les plus importants du 20e siècle (prix Nobel 1965) aborde la science, avec humour, rigueur et avec un réel plaisir de chercher, fouiner, explorer...
• —. 1974. "Cargo Cult Science" (PDF). Engineering and Science 37 (7).
• —. 2007. The Meaning of It All: Thoughts of a Citizen-Scientist. London: Penguin.
• —. 2008. Perfectly Reasonable Deviations From the Beaten Track: The Letters of Richard P. Feynman. Reprint. Basic Books.
• —. 2012. Don’t You Have Time to Think? London: Penguin.
• —., and Jeffrey Robbins. 2005. The Pleasure of Finding Things Out: The Best Short Works of Richard P. Feynman. Basic Books.
• -., and Leighton, Ralph. 1988. What Do You Care What Other People Think? Further Adventures of a Curious Character. W. W. Norton.
• Gleick, James. 2011. Genius: The Life and Science of Richard Feynman. Open Road Media.

• There are numerous talks with Richard Feynman on Youtube (including famous lectures given by him), just search for Richard Feynman and watch, for instance: Fun to Imagine, Ten times R. Feynman blew Our Minds, Why, Bill Gates: The Best Teacher I ever had . There is also a video in the CERN library: The Pleasure of Finding Things Out

• “Being wrong isn’t a bad thing like they teach you in school. It is an opportunity to learn something.”
• The first principle is that you must not fool yourself and you are the easiest person to fool.
• Reality must take precedence over public relations, for nature cannot be fooled.
• It doesn't matter how beautiful your theory is, it doesn't matter how smart you are. If it doesn't agree with experiment, it's wrong.
• It is in the admission of ignorance and the admission of uncertainty that there is a hope for the continuous motion of human beings in some direction that doesn't get confined, permanently blocked, as it has so many times before in various periods in the history of man.
• I learned very early the difference between knowing the name of something and knowing something.[video]
• Teach your children early what you learned late.

• There a many websites and social media with quotes by Feynman, e.g Goodreads.com
, Rightattitudes.com"

• Challenger Desaster (and the role of R. Feynman)
• Critical thinking